Finding a time to reach the limit in a word problem on exponential growth or decay
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We are told that each year the value of the laptop is 75% of the value of the value of the previous year. This means that every year the current value of the laptop is multiplied by 0.75. Then if v is the original value of the laptop its value after t years is given by:
[tex]V(t)=v0.75^t[/tex]We need to find after which year V(t) is equal to 500 or less then we have V(t)≤500 and since the original value of the laptop was 4200 we have v=4200:
[tex]4200*0.75^t\leq500[/tex]We divide both sides by 4200:
[tex]\begin{gathered} \frac{4200\times0.75^t}{4200}\leqslant\frac{500}{4200} \\ 0.75^t\leq\frac{5}{42} \end{gathered}[/tex]Then we apply the logarithm to both sides:
[tex]\log_{10}(0.75^t)\leqslant\log_{10}(\frac{5}{42})[/tex]Then we use the property of logarithm regarding exponents:
[tex]\begin{gathered} \operatorname{\log}_{10}(0.75^{t})\leqslant\operatorname{\log}_{10}(\frac{5}{42}) \\ t\log_{10}(0.75)\leq\operatorname{\log}_{10}(\frac{5}{42}) \end{gathered}[/tex]And we divide both sides by the logarithm of 0.75 (we change the inequality symbol because log(0.75) is negative):
[tex]\begin{gathered} \frac{t\operatorname{\log}_{10}(0.75)}{\operatorname{\log}_{10}(0.75)}\ge\frac{\log_{10}(\frac{5}{42})}{\operatorname{\log}_{10}(0.75)} \\ t\ge\frac{\log_{10}(\frac{5}{42})}{\operatorname{\log}_{10}(0.75)} \end{gathered}[/tex]Then we get:
[tex]t\ge7.398[/tex]So the laptop's value is less than $500 after 7.398 years.
AnswerSince we are requested to write a whole number as the answer and the smallest whole number that is bigger than 7.398 is 8 we have that the answer is 8 years.
Related Questions
The table below shows the probability distribution of students in a highschool with 1500 students. What is the expected value for the ageof arandomly chosen student?Age131415161718Probability.0.010.250.300.280.150.01A. 15.28B. 15.64C. 15.34D. 15.36
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Solution
We are required to determine the expected value of the given distribution
The formula for expected value is shown below
Thus,
[tex]\begin{gathered} Expected\text{ value =13\lparen0.01\rparen+14\lparen0.25\rparen+15\lparen0.30\rparen+16\lparen0.28\rparen+17\lparen0.15\rparen+18\lparen0.01\rparen} \\ = \end{gathered}[/tex][tex]=0.13+3.5+4.5+4.48+2.55+0.18[/tex][tex]=15.34[/tex]The correct option is C
Rationalize the denominator and simplify:
√5a+√5
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Be sure to include the correct unit in your answer
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The fence required is:
[tex]388.3125ft^2[/tex]Explanation:For the farmer to build an accurate fence, he needs to know the area of the rose garden. The area is the sum of the area of the rectangle and the area of the semicircle.
The area of the rectangle is:
[tex]\begin{gathered} A=wl \\ =15ft\times20ft \\ =300ft^2 \end{gathered}[/tex]The area of the semicircle is:
[tex]\begin{gathered} A=\frac{\pi}{2}r^2 \\ \\ \text{Where r is the radius }=\frac{15}{2}=7.5ft,\pi=3.14 \\ \\ A=\frac{3.14}{2}(7.5)^2=88.3125ft^2 \end{gathered}[/tex]The area of the rose garden is:
[tex]300ft^2+88.3125ft^2=388.3125ft^2[/tex]Determine the measure of ∠BFE.Question options:1) 112°2) 111°3) 69°4) 224°
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We apply tangent-tangent theorem:
[tex]\begin{gathered} one\text{ tangeht = 9} \\ 2nd\text{ tangent = 2x - 1} \end{gathered}[/tex]The tangent segement from the same external points are congruent:
[tex]9\text{ = 2x - 1}[/tex][tex]\begin{gathered} Add\text{ 1 to both sides:} \\ 9\text{ + 1 = 2x} \\ 10\text{ = 2x} \\ \text{divide both sides by 2:} \\ \frac{10}{2}\text{ = }\frac{2x}{2} \\ x\text{ = 5} \end{gathered}[/tex]I haven’t got a clue about what it is or what to do
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EXPLANATION
Rotating the shape , give us the third shape form.
Si A = 5x 2 + 4 x 2 - 2 (3x2), halla su valor numérico para x= 2.
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Based on the calculations, the numerical value of A is equal to 12.
How to determine the numerical value of A?In this exercise, you're required to determine the numerical value of A when the value of x is equal to 2. Therefore, we would evaluate the given equation based on its exponent as follows:
Numerical value of A = 5x² + 4x² - 2(3x²)
Numerical value of A = 5(2)² + 4(2)² - 2(3 × (2)²)
Numerical value of A = 5(4) + 4(4) - 2(3 × 4)
Numerical value of A = 20 + 16 - 24
Numerical value of A = 36 - 24
Numerical value of A = 12
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Complete Question:
If A = 5x² + 4x² - 2(3x²), find its numerical value for x = 2.
3. In one linear function, when you subtracteach y-coordinate from the x-coordinate,the difference is 3. If the x-coordinate isnot greater than 10 and the y-coordinateis a positive whole number, how manyordered pairs are there?
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Problem
3. In one linear function, when you subtract each y-coordinate from the x-coordinate, the difference is 3. If the x-coordinate is not greater than 10 and the y-coordinate is a positive whole number, how many ordered pairs are there?
Solution
Here are the conditions
x- y= 3
x <10
y >0
And then we have these as possible answers:
4-1 =3
5-2= 3
6-3=3
7-4=3
8-5=3
9-6=3
Then the total possible pairs are: 6
Look at the graphs and their equations below. Then fill in the information about the coefficients A, B, C, and D.
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Given:
Aim:
We need to find the coordinates and The sign of the equation.
Explanation:
[tex]We\text{ know that y=a\mid x\mid is upside and y}\ge\text{0 when a >0 and downside and y}\leq\text{owhen a<0}[/tex]The coefficient of the given functions are
[tex]y=A|x|\text{ is positive}[/tex][tex]y=B|x|\text{ is positive}[/tex][tex]y=C|x|\text{ is negative}[/tex][tex]y=D|x|\text{ is negative}[/tex]The coefficient is closest to zero.
Comparing the graph of y=A|x| and y=B|x|, we get y=A|x| is wider than y=B|x|.
[tex]A
Comparing the graph of y=C|x| and y=D|x|, we get y=D|x| is wider than y=C|x|.
[tex]CComparing the graph of y=A|x| and y=C|x|, we get y=C|x| is wider than y=A|x|.
[tex]C The coefficient is closest to zero y=C|x|.The coefficient with the greatest value.
Comparing the graph of y=B|x| and y=D|x|, we get y=D|x| is wider than y=B|x|.
[tex]D The coefficient with the greatest value is y=B|x|. .The employees in a firm earn $8.50 an
hour for the first 40 hours per week, and
1.5 times the hourly rate for any hours
worked over 40. How much does an
employee who works 52 hours in one
week eam?
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Using mathematical operations, we know that the salary of a person working for 52 hours a week will be $493.
What are mathematical operations?An operation is a function in mathematics that transforms zero or more input values into a clearly defined output value. The operation's arity is determined by the number of operands. The rules that specify the order in which we should solve an expression involving multiple operations are known as the order of operations. PEMDAS stands for Parentheses, Exponents, Multiplication, Division, and Addition Subtraction (from left to right).So, the amount earned by a person who works 52 hours a week:
Salary if a person works for 40 hours: $8.50 per hourSalary if a person works for more than 40 hours: 1.5 times $8.50 per hour that is, 8.50 × 1.5 = $12.75 per hour.So, if a worker works for 52 hours, his salary will be:
52 - 40 = 12 Hours40 × 8.50 = $34012 × 12.75 = $153Sum: $493Therefore, using mathematical operations, we know that the salary of a person working for 52 hours a week will be $493.
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I need you to make a problem and solve it on the side and explain how explain it I’m making a practice test and I can show you examples of how I did the others This are the topics you can choose fromTopic 1: is the relation a function- domain and range Topic 2: zero is of a function
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For topic (1), we have the following question:
Which of the following is a function: y=x² or x=y²?
Identify domain and range of each equation.
We can identify a given relation if it is a function or not by identifying the number of possible values of y.
The equations below are both relations.
[tex]y=x^2\text{ and }x=y^2[/tex]However, only one of them is a function.
For the first equation, note that for each value of x, there is only one value of y. Some of the points on the equation are as follows.
[tex]\begin{gathered} x=-2 \\ y=x^2^{} \\ y=(-2)^2=4 \\ \\ x=0 \\ y=x^2 \\ y=0^2=0 \\ \\ x=2 \\ y=x^2 \\ y=2^2 \\ y=4 \end{gathered}[/tex]Thus, the equation passes through the following points.
[tex](-2,4),(0,0),(2,4)[/tex]Notice that no value of x is repeated. Therefore, the given relation is a function.
We can also determine it using graphs. The image below is the graph of the first equation.
If we test it using the vertical line test, no vertical line can pass through the graph twice. Therefore, it shows that the equation is a function.
On the otherhand, the other equation is not a function. This is because when we substitute -2 and 2 to the value of y, we will have the same value of x, which is equal to 4.
[tex]\begin{gathered} y=-2^{} \\ x=y^2 \\ x=(-2)^2=4 \\ \\ y=2 \\ x=y^2^{} \\ x=2^2=4 \end{gathered}[/tex]Since there are two values of y for only one value of x, the equation must not be a function.
To illustrate this using its graph, we can notice that the vertical line below passes through two points on the graph when x=4.
Therefore, the second equation is not a function.
As for the domain and range, we can obtain it from both graphs.
The domain the set of all possible values of x. Thus, for the first equation, since it extends indefinitely to the left and right, the domain must be from negative infinity to positive infinity.
[tex]D_1\colon(-\infty,\infty)[/tex]On the otherhand, since the second equation extends indefinitely to the right from 0, the domain must be from 0 to positive infinity, inclusive.
[tex]D_2\colon\lbrack0,\infty)[/tex]As for the range, it is the set of all possible values of y.
Thus, for the first equation, since the graph extends indefinitely upwards from 0, the range must be from 0 to positive infinity, inclusive.
[tex]R_1\colon\lbrack0,\infty)[/tex]On the otherhand, the graph of the second equation extends indefinitely upwards and downwards. Thus, its range must be from negative infinity to positive infinity.
[tex]R_2\colon(-\infty,\infty)[/tex]To summarize, here are the questions and the answers for each question.
Which of the following is a function: y=x² or x=y²?
Answer: y=x²
Identify domain and range of each equation.
Answer:
For y=x²:
[tex]\begin{gathered} D\colon\text{ (-}\infty,\infty\text{)} \\ R\colon\lbrack0,\infty) \end{gathered}[/tex]For x=y²:
[tex]\begin{gathered} D\colon\lbrack0,\infty) \\ R\colon(-\infty,\infty) \end{gathered}[/tex]I’m not sure how to graph the equation and not sure what it means by “interpret”
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(a) Graphing the equation
(i) let x = 0 ; then
y = -0.05 (0) +16
∴ y = 16
Point 1 = ( 0;16 )
(ii) let y = 0 , then
0 = -0.05x +16
0.05x = 16
x = 16 /0.05
∴ x = (320 )
point 2 = ( 320; 0 )
The graph of the line ( y = -0.05x+16) will then be as follows :
(b) Interpret the x and y intercept :{To interpret means to explain in details or translate in writing the meaning of the values of x and y . }
• x represents the number of miles travelled
,• y represents gasoline used i gallons
Interpretation:
• when ,x is 0 miles, , the ,gasoline ,is sitting at, 16 gallons.,( this might be the initial stage of travelling)
,• however, when the, person has travelled 320 miles,, all gasoline is ,completly used up and sits at 0 gallons, .( this might be the end stage of travelling)
drag the location of each ordered pair after a reflection over the x axis stated. then, drag the correct algebraic representation of the reflection to the white box. answer choices: (y, x), (-2,-6),(x,-y),(-3,-2),(5,8),(-5,-8),(-x, y),(-6,-6),(-6,-1),(2,-6),(6,-1),(3,2),(-x, -y),(-7,-2),(6,-6),(7,2)
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Reflection over the x-axis transform the point (x, y) into (x, -y)
Applying this rule to the vertex of the triangle ABC, we get:
A(-6, 6) → A'(-6, -6)
B(-2, 6) → B'(-2, -6)
C(-6, 1) → C'(-6, -1)
Algebraic representation: (x, -y)
If the correlation coefficient is 1, then the relation is a __________________.perfect positive correlationperfect negative correlationweak negative correlationweak positive correlation
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Given:
The correlation coefficient is 1.
Required:
What type of correlation is it?
Explanation:
A coefficient of -1.0 indicates a perfect negative correlation, and a correlation of 1.0 indicates a perfect positive correlation.
Answer:
Hence, correlation coefficient is 1 then relation is perfect positive correlation.
Question 3 of 14What are the factors of the product represented below?TILESX2 X2 X2 X2X X X XA. (2x + 1)(4x + 3)B. (4x + 2)(3x + 1)C. (8x + 1)(x+2)D. (4x + 1)(2x + 3)
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Hi!
To solve this exercise, we can analyze the sides of this rectangle, which indicate the size of each side.
Let's do it:
On the superior side, we have: x+x+x+x+1, which means 4x+1, right?
On the left side, we have: x+x+1+1+1, or 2x+3
So, we can say that the factors of this rectangle are (4x+1)*(2x+3), last alternative.
find the sum.(7-b) + (3) +2 =
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During a food drive, a local middle school collected 3,195…
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Answer:
100 cans
Explanation:
• The total number of canned food items collected = 3,195
,• The number of classrooms that participated = 28
To estimate the number of items each classroom donated, divide 3195 by 28.
[tex]\frac{3195}{28}\approx\frac{3000}{30}=100[/tex]Note: Round to a whole number since the number of cans cannot be a decimal.
Each class donated about 100 cans.
During a Super Bowl day, 19 out of 50 students wear blue-colored jersey upon entering the campus. If there are 900 students present on campus that day, how many students could be expected to be wearing a blue-colored jersey? T T
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The figure below is a trapezoid:10011050mZ1 =m2 =mZ3=Blank 1:Blank 2:Blank 3:
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STEP 1: Identify and Set Up
We have a trapezoid divided by a straight line that divides it assymetrically. We know from the all too famous geometric rule that adjacent angles in a trapezoid are supplementary. Mathematically, we can express thus:
[tex]100^o+<2+<3^{}=180^o=50^o+110^o+<1[/tex]Hence, from this relation, we can find our unknown angles.
STEP 2: Execute
For <1
[tex]\begin{gathered} 180^o=50^o+110^o+<1 \\ 180^o=160^o+<1 \\ \text{Subtracting 160}^o\text{ from both sides gives} \\ <1=180-120=60^o \end{gathered}[/tex]<1 = 60 degrees
For <2 & <3
We know from basic geometry that a transversal across two parallel lines gives a pair of alternate angles and as such, <1 = <3 = 60 degrees
We employ our first equation to solve for <2 as seen below:
[tex]\begin{gathered} 100^o+<2+<3^{}=180^o \\ 100^o+<2+60^o=180^o \\ 160^o+<2=180^o \\ \text{Subtracting 160}^{o\text{ }}\text{ from both sides gives:} \\ <2=180-160=20^o \end{gathered}[/tex]Therefore, <1 = <3 = 60 degrees and <2 = 20
19. Write in algebraic terms: six times a number, minus five times the number, plus eight.
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Let the number be a
6a x 5a + 8
Over which interval(s) is the function decreasing?A) -4 < x < 3B) -0.5 < x < ∞C) -∞ < x < -0.5D) -∞ < x < -4
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In the interval where the function is decreasingcreasing, the input or x values increase as the output or y values decrease. Looking at the graph, moving from the left to the right, the values of x are increasing whie the values of y are decreasing. This trend continued till we got to x = 0.5. Thus, in the interval from negative infinity to x = - 0.5, the function was decreasing.
The correct option is C
The speedometer on Leona's car shows the speed in both miles per hour and kilometers per hour. Using 1.6 km as the equivalent for 1 mi, find the mile per hour rate that is equivalent to 40 kilometers per hour.
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To find the mile per hour rate equivalent to 40 km per hour, let's convert 40km to miles using the given equivalence in the question.
[tex]\begin{gathered} 1.6\operatorname{km}=1mi \\ 40\operatorname{km}\times\frac{1mi}{1.6\operatorname{km}}=\frac{40\operatorname{km}mi}{1.6\operatorname{km}}=25mi \end{gathered}[/tex]Therefore, 40 km = 25 miles.
The mile per hour rate equivalent to 40km per hour is 25 miles per hour.
In 2011, an earthquake in Chile measured 8.3 on the Richter scale. How many times more intense was thisearthquake then than the 2011 earthquake in Papa, New Guinea that measured 7.1 on the Richter scale? Roundthe answer to the nearest integer.
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SOLUTION:
Step 1:
In this question, we are given that:
In 2011, an earthquake in Chile measured 8.3 on the Richter scale. How many times more intense was this earthquake then than the 2011 earthquake in Papa, New Guinea that measured 7.1 on the Richter scale?
Round the answer to the nearest integer.
Step 2:
From the question, we are to use this formula:
Now, we have that:
[tex]\begin{gathered} M_2-M_1=\log (\frac{I_2}{I_1}) \\ \text{where M}_2=\text{ 8.3} \\ \text{and} \\ M_1=\text{ 7. 1} \end{gathered}[/tex]Hence, we have that:
[tex]\begin{gathered} \text{8. 3 - 7. 1 = log ( }\frac{I_2}{I_1}) \\ 1.2=log_{10}\text{ (}\frac{I_2}{I_1}) \\ (\frac{I_2}{I_1})\text{ = }10^{1.2} \end{gathered}[/tex]CONCLUSION:
The final answer is:
[tex](\frac{I_2}{I_1})=10^{1.\text{ 2}}[/tex]a mother duck lines her 8 ducklings up behind her. in how many ways can the ducklings line up?
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In position one, we can have any of the 8 ducks
In position two, we can have 7 ducks, since one has to occupy position one
and so on
then, we have:
[tex]8\cdot7\cdot6\cdot5\cdot4\cdot3\cdot2\cdot1=8![/tex]the factorial of 8 is 40320
Look at triangles A through F shown in the rectangles below.Which triangles are acute triangles?
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The acute triangles are those whose all 3 angles have a measure less than 90 degrees.
We need to follow the next image:
Let us check each triangle.
Triangle A:
It has a right angle, hence, it can not be an acute triangle.
Triangle B:
All three sides are less than 90 degrees. Hence, it is an acute triangle
Triangle C:
It has an angle with a measure of more than 90 degrees. Hence, it can not be an acute triangle.
Triangle D
All three sides are less than 90 degrees. Hence, it is an acute triangle.
Triangle E
It has a side with a measure of more than 90 degrees. Hence, it can not be an acute triangle.
Triangle F
It has a right angle, hence, it can not be an acute triangle.
Hence, the correct answer is H. B and D
Which equation represents the values in the table? x–1012y–13711A.y = 4x + 3B.y = −x − 1C.y = 3x − 1D.y = 1/4x − 3/4
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We know it's a linear function, which is like
[tex]f(x)=mx+b[/tex]We can find the slope "m" of the linear function doing
[tex]m=\frac{y_2-y_1}{x_2-x_1}[/tex]There the points x₂, x₁, y₂ and y₁ we can take what's more convenient for us, just be careful, if you do x₁ = 0, you must take the correspondent y₁, the value of y on the same column, therefore y₁ = 3, for example.
I'll do x₁ = 0 which implies y₁ = 3 and x₂ = 1 which implies y₂ = 7. Therefore
[tex]\begin{gathered} m=\frac{7_{}-3}{1_{}-0_{}} \\ \\ m=\frac{7_{}-3}{1_{}}=4 \end{gathered}[/tex]Therefore the slope is m = 4, then
[tex]y=4x+b[/tex]To find out the "b" value we can use the fact that when x = 0 we have y = 3, therefore
[tex]\begin{gathered} y=4x+b \\ \\ 3=4\cdot0+b \\ \\ 3=b \\ \end{gathered}[/tex]Then b = 3, our equation is
[tex]y=4x+3[/tex]The correct equation is the letter A.
O is the center of the regular hexagon below. Find its perimeter. Round to the nearest tenth if necessary.
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To solve this problem, we have to find the side length and multiply it by the number of sides of the figure.
To find the length side we will use the following formula:
[tex]ap=\sqrt[]{I^2-(\frac{I^{}}{2})^2}\text{.}[/tex]Where ap is the length of the apothem, and I is the side length.
Substituting the given values, we get:
[tex]10=\sqrt[]{I^2-(\frac{I}{2})^2}.[/tex]Solving the equation for I, we get:
[tex]\begin{gathered} \\ I=\frac{2\times10}{\sqrt[]{3}}. \end{gathered}[/tex]Therefore, the perimeter of the hexagon is:
[tex]6I=6\times\frac{2\times10}{\sqrt[]{3}}\approx69.3\text{ units.}[/tex]Answer:
[tex]69.3\text{ units.}[/tex]If the trend shown in the graph above continued into the next year, approximately how many sport utility vehicles were sold in 1999?
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ANSWER :
EXPLANATION :
what is a youth group that
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(3+ 1i) (2 - 2i)
open the parenthesis
3(2 - 2i) + 1i(2 - 2i) (note: i² = -1)
6 - 6i + 2i + 2
Rearrange
6 + 2 - 6i + 2i
8 - 4i
comparing with a + bi
The real number a equals 8
The real number b equals -4
a. Rotate the letter W 180° around the origin. Then translate the image up 4 units. Draw the final image. What new letter did you form? b. Is the new letter congruent to the original letter? Explain.
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ANSWER and EXPLANATION
We have letter W on the graph.
The cordinates of its vertices are:
(0, 4), (1, 0), (2, 2), (3, 0), (4, 4)
Now, on a cartesian plane, (x - y plane), we have 4 quadrants. The letter is on the first quadrant.
Because it rotates 180 degrees around the origin, it means that it mmoves by 2 quadrants:
So, it moves from quadrant 1 to quadrant 4.
The new cordinates become:
(0, -4), (-1, 0), (-2, -2), (-3, 0), (-4, -4)
Then it is translated 4 units up, so we add 4 units to each of the y values (Remember that cordinates are written as (x, y)):
(0, 0), (-1, 4), (-2, 2), (-3, 4), (-4, 0)
Now, plot those:
a) It forms the letter M.
b) For one shape to be congruent to another, it means that they have the same size. So, yes, the M is congruent to the W.
5) Find the volume of the cylinder whose radius is 10in and height is 20in.V-π r 2 h