which expression could be substituted for x in the second equation to find the value of y?
Answers
Substitution
We have the system of equations:
x + 2y = 20
2x - 3y = -1
To solve it with the substitution method, we need to solve the first equation for x and substitute it in the second equation.
Subtracting 2y to the first equation:
x = -2y + 20
This expression corresponds to choice B.
Related Questions
5. (20 x 5 + 10) - (8 × 8 - 4)=
a. 58
b. 50
c. 40
Answers
Answer:
b. 50
Step-by-step explanation:
20 x 5 + 10 = 110
8 × 8 - 4 = 60
110 - 60 = 50
Answer:
b. 50
Step-by-step explanation:
(20x5+10)- (8x8-4)
(100+10) - (64-4)
110 - 60
equals 50
Find the probability of at least 2 girls in 6 births. Assume that male and female births are equally likely and that the births are independent events.0.6560.1090.2340.891
Answers
We need to use Binomial Probability.
Of 6 births, we want to find the probability of at least 2 of them being girls.
To solve this, we need to find:
Probability of exactly 2 girls
Probability of exactly 3 girls
Probability of exactly 4 girls
Probability of exactly 5 girls
Probability of exactly 6 girls
If we add all these probabilities, we get the probability of at least 2 girls.
To find the probabilities, we can use the formula:
[tex]_nC_r\cdot p^r(1-p)^{n-r}[/tex]Where:
n is the number of trials (in this case, the number of total births)
r is the number of girls we want to find the probability
p is the probability of the event occurring
[tex]_nC_r\text{ }is\text{ }the\text{ }combinatoric\text{ }"n\text{ }choose\text{ }r"[/tex]The formula for "n choose r" is:
[tex]_nC_r=\frac{n!}{r!(n-r)!}[/tex]Then, let's find the probability of exactly 2 girls:
The probability of the event occurring is:
[tex]P(girl)=\frac{1}{2}[/tex]Because there is a 50% probability of being a girl or a boy.
let's find "6 choose 2":
[tex]_6C_2=\frac{6!}{2!(6-2)!}=\frac{720}{2\cdot24}=15[/tex]Now we can find the probability of exactly 2 girls:
[tex]Exactly\text{ }2\text{ }girls=15\cdot(\frac{1}{2})^2(1-\frac{1}{2})^{6-2}=15\cdot\frac{1}{4}\cdot(\frac{1}{2})^4=\frac{15}{4}\cdot\frac{1}{16}=\frac{15}{64}[/tex]We need to repeat these calculations for exactly 3, 4, 5, and 6 girls:
Exactly 3 girls:
let's find "6 choose 3":
[tex]_6C_3=\frac{6!}{3!(6-3)!}=\frac{720}{6\cdot6}=20[/tex]Thus:
[tex]Exactly\text{ }3\text{ }girls=20\cdot(\frac{1}{2})^3(1-\frac{1}{2})^{6-3}=20\cdot\frac{1}{8}\cdot\frac{1}{8}=\frac{5}{16}[/tex]Exactly 4 girls:
"6 choose 4":
[tex]_6C_4=\frac{6!}{4!(6-4)!}=\frac{720}{24\cdot2}=15[/tex]Thus:
[tex]Exactly\text{ }4\text{ }girls=15\cdot(\frac{1}{2})^4(1-\frac{1}{2})^{6-4}=15\cdot\frac{1}{16}\cdot\frac{1}{4}=\frac{15}{64}[/tex]Exactly 5 girls:
"6 choose 5"
[tex]_6C_5=\frac{6!}{5!(6-5)!}=\frac{720}{120}=6[/tex]Thus:
[tex]Exactly\text{ }5\text{ }girls=6\cdot(\frac{1}{2})^5(1-\frac{1}{2})^{6-5}=6\cdot\frac{1}{32}\cdot\frac{1}{2}=\frac{3}{32}[/tex]Exactly 6 girls:
"6 choose 6"
[tex]_6C_6=\frac{6!}{6!(6-6)!}=\frac{720}{720\cdot0!}=\frac{720}{720}=1[/tex]Thus:
[tex]Exactly\text{ }6\text{ }girls=1\cdot(\frac{1}{2})^6(1-\frac{1}{2})^{6-6}=\frac{1}{64}\cdot(\frac{1}{2})^0=\frac{1}{64}[/tex]now, to find the answer we need to add these 5 values:
[tex]\frac{15}{64}+\frac{5}{16}+\frac{15}{64}+\frac{3}{32}+\frac{1}{64}=\frac{57}{64}=0.890625[/tex]To the nearest tenth, the probability of at least 3 girls is 0.891, thus, the last option is the correct one.
Find the length of AC
Answers
The rule of the length of an arc is
[tex]L=\frac{x}{360}\times2\pi\text{ r}[/tex]Where L is the length of the arc
x is the central angle subtended by the arc
r is the radius of the circle
∵ BC = r
∵ BC = 16 ft
∴ r = 16
∵ < ABC is a central angle subtended by the arc AC
∴ ∵ < ABC = 51 degrees
∴ x = 51
→ Substitute the values of x and r in the rule above to find The length of arc AC
[tex]\begin{gathered} AC=\frac{51}{360}\times2\times3.14\times16 \\ AC=14.23466667 \end{gathered}[/tex]→ Round it to 2 decimal places
∴ AC arc = 14.23 ft
Find a unit vector u with the same direction as v = : (-3, 8)
Answers
Given:
The vector
[tex]v=<-3,8>[/tex]Required:
To find the unit vector u with the same direction.
Explanation:
Unit formula is the vector is divided by its magnitude.
Now the magnitude of v is,
[tex]\begin{gathered} mag.v=\sqrt{(-3)^2+8^2} \\ =\sqrt{9+64} \\ =\sqrt{73} \end{gathered}[/tex]Now the unit vector is,
[tex]u=<-\frac{3}{\sqrt{73}},\frac{8}{\sqrt{73}}>[/tex]Final Answer:
[tex]u=<-\frac{3}{\sqrt{73}},\frac{8}{\sqrt{73}}>[/tex]Find the value of x so that f(x) = 7.YA6f4200246XX =
Answers
The blue line in the graph indicates the function f(x).
The values in the y-axis are the value of the function, that is, the value of f(x) for a given value of x. The x-axis indicates what value of x generates the value in the y-axis.
So, if we want to find the value of x that gives us f(x) = 7, we need to find where is the value '7' in the y-axis, then we draw an horizontal line from this value toward the line of the function (blue line).
This horizontal line will intersect the function in a certain point. This point is where the function has the value 7.
Now, to find the value of x of this point, we draw a vertical line from this point downwards, until it intersects the x-axis.
This way, looking at the image, we can see that the value of x that gives us f(x) = 7 is the value x = 5.
White the standard form of the equation of the line through the given point with the given slope.
Answers
The standard form equation of a line is expressed as
Ax + By = C
where
A, B and C are real numbers and A and B are not both zero. From the information given,
the line passes through(- 2, 5) and slope = - 4
We would find the y intercept of the line, c by substituting slope, m = - 4, x = - 2 and y = 5 into the slope intercept equation which is expressed as
y = mx + c
Thus, we have
5 = - 4 * - 2 + c
5 = 8 + c
c = 5 - 8 = - 3
Thus, the equation of the line in the slope intercept form is
y = - 4x - 3
We would convert it to standard form. Thus, we have
y + 4x = - 3
4x + y = - 3
Thus, the equation in standard form is
4x + y = - 3
The function h(x) is a transformed function of f(x) = |x|. The transformation is as follows: 1 units vertical shift up, 4 units horizontal shift left.a). Write the transformed equation, h(x).b). Graph f(x) and h(x) on the same coordinate plane. Be sure to label the functions f(x) and h(x). This must be graphed by hand or by using the tools in Word.
Answers
To transform a function 1 unit up, we add 1 outside of the function
h(x) = |x| +1
shifting it 4 units to the left, we will add 4 units from x inside
h(x) = |x+4| +1
The transformed function is
h(x) = |x+4| +1
how do I know which picture goes with the correct equation
Answers
If B is between A and C, but B is not midpoint, then the graph would be
The equation would be
[tex]AC=AB+BC[/tex]On the other hand, if B is between A and C, and B is a midpoint, the graph would be
The equation would be
[tex]AB=BC[/tex]can i get some help please?
Answers
convert this number into scientific notation 0.00098
Answers
We have to convert the number into scientific notation.
The number is 0.00098.
We start by expressing it as a fraction.
If we divide it by 10, we can express it as:
[tex]\frac{0.00098\cdot10}{10}=\frac{0.0098}{10}[/tex]Dividing by 10 is not enough. In the same way, we have to look a numerator that is multiple of 10 that gives us a numerator that is 9.8.
We would get:
[tex]\frac{0.00098\cdot10000}{10000}=\frac{9.8}{10000}[/tex]Now we have the numerator we need.
We now express the denominator 10,000 as a power of 10 and we get the number in scientific notation as:
[tex]\frac{9.8}{10000}=\frac{9.8}{10^5}=9.8\cdot10^{-5}[/tex]Answer: 0.00098 = 9.8 * 10^(-5)
complete the following: 1. Find the locus of points whose: (a) ordinate saquare decressed by the square of the abscissa is the sum of the coordinates
Answers
P(x,y) is the coordinate point of the locus
ordinate is y
abscissa is x
Following the sentence we have
ordinate square y^2
decreased means subtract
square of the abscissa x^2
is means equal
the sum of the coordinates x+y
[tex]y^2-x^2=x+y[/tex]Farrah borrows $18,000 to purchase a new car. The annual interest rate for the 60-month loan is 4.3%.If she makes all the monthly payments, what is the total amount of interest she will pay on the loan?
Answers
SOLUTION:
Step 1:
In this question, we are given the following:
Principal = $ 18,000
Time = 60 month = 60/ 12 = 5 years
Interest = 4. 3%
Step 2:
The total amount she will pay at the end of the 5 -year period is given as follows:
[tex]\begin{gathered} A\text{ = P ( 1 + }\frac{R}{100})^t \\ A\text{ = 18000 ( 1 + }\frac{4.3}{100})^5 \\ \end{gathered}[/tex][tex]\begin{gathered} A\text{ = 22,217. 4416} \\ A\text{ }\approx\text{ }22,217.44\text{ dollars} \end{gathered}[/tex]Step 3:
Now, we have that the amount = 22, 217. 44 dollars.
And the Principal = 18,000 dollars
If she makes all the monthly payments,
Then, the total amount of interest she will pay on the loan is:
[tex]22,\text{ 217. 44 - 18,000 = 4,217. 44 dollars}[/tex]CONCLUSION:
The total amount of interest she will pay on the loan = 4, 217. 44 dollars.
Madeline is a salesperson who sells computers at an electronics store. She makes a base pay of $80 each day and then is paid a $20 commission for every computer sale she makes. Make a table of values and then write an equation for P, in terms of x, representing Madeline's total pay on a day on which she sells x computers.
I need the Equation.
Answers
The linear equation that gives the values of P in terms of x which is Madeline's total pay on a given day is; P + 20·x + 80
What is an equation in mathematics?An equation consists of two expressions that are joined by an equal to sign to complete a mathematical statement.
The given parameters are:
Madeline's daily base pay = $80
Madeline's commission for each computer sold = $20
The given table of values is presented as follows:
Daily pay, in Dollars, P; [tex]{}[/tex] 80, 100, 120, 140
Number of computers sold, x; [tex]{}[/tex] 0, 1, 2, 3
From the above table of values, given that the independent variable, x, is increasing at a constant rate, and that the first difference is constant, we have that the relationship is a linear relationship, that has an equation of the form; P = m·x + c
Where:
m = The slope
c = The y-intercept
The slope which gives the ratio of the rise to the run of the graph is given by the equation; [tex]m = \dfrac{100-80}{1-0} =20[/tex]
The equation in point and slope form is therefore: P - 80 = 20·(x - 0) = 20·x
P - 80 = 20·x
P = 20·x + 80
Learn more about writing linear equations here:
https://brainly.com/question/4074386
#SPJ1
What values of z and y make angle ABC = RPM?
Answers
Two triangles are said to be congruent if all three corresponding sides are equal and all the three corresponding angles are equal in measure.
If triangles ABC and RPM are congruent, it means that:
[tex]\begin{gathered} AB=RP \\ BC=PM \\ AC=RM \\ m\angle A=m\operatorname{\angle}R \\ m\operatorname{\angle}B=m\operatorname{\angle}P \\ m\operatorname{\angle}C=m\operatorname{\angle}M \end{gathered}[/tex]For x, we have that:
[tex]\begin{gathered} BC=PM \\ BC=43 \\ PM=3x-8 \end{gathered}[/tex]Thus, we have that:
[tex]\begin{gathered} 43=3x-8 \\ 3x=43+8=51 \\ x=\frac{51}{3} \\ x=17 \end{gathered}[/tex]For y, we have:
[tex]\begin{gathered} m\operatorname{\angle}B=m\operatorname{\angle}P \\ m\operatorname{\angle}B=12y\degree \\ m\operatorname{\angle}P=62.4\degree \end{gathered}[/tex]Thus, we have that:
[tex]\begin{gathered} 12y=62.4 \\ y=\frac{62.4}{12} \\ y=5.2 \end{gathered}[/tex]Therefore, the answers are:
[tex]x=17,y=5.2[/tex]The LAST OPTION is correct.
ifvx varies directly as y and x =36 when y=6 find x when y=9
Answers
Answer:
54
Step-by-step explanation:
Hello!
A direct variation can be expressed as [tex]y = ax[/tex], where a is multiplied.
As you can see, x is 6 times greater than y, proving that when y is 6, x is 36 (6*6 = 36).
Therefore, we can say that if y is 9, we can multiply the value by 6 to find the x-value:
x = 6 * 9x = 54So the value of x is 54.
Select the similarity transformation(s) that make ABC similar to EDC.
Answers
Given the triangles ABC and EDC
We will find the transformation that makes the triangles are similar
As shown: the triangles are reflected over the y-axis
the rule of the reflection over the y-axis will be as follows:
[tex](x,y)\rightarrow(-x,y)[/tex]And as shown, the length of the side AB = 3 units
And the length of the side ED = 1 units
So,
[tex]ED=\frac{1}{3}AB[/tex]So, the answer will be:
D) (x,y) ⇒ (-x, y)
E) (x,y) ⇒ (1/3 x, 1/3 y)
8. Kayla finds the multiplication
facts for 12
by doubling the multiplication facts for 6.
Does Kayla's strategy work?
Use words, numbers, or pictures to explain.
Answers
A strategy is a way to manipulate numbers, use connections and interactions between numbers to solve an issue. For each procedure, there are a few key tactics. The first thing you do with the statistics is frequently used to categorize, characterize, or label a technique.
What is a doubling strategy?By doubling the multiplication facts for 6, Kayla discovers the 12 multiplication facts.The participant does as instructed, multiplying the number twice or three times. Lily, for instance, rolls "4" and "DDD." She believes that double 4 is equal to 8, double 8 to 16, and double 16 to 32. Four times eight equals 32.A number is simply doubled when multiplied by two, according to the two times table. Any number plus itself is the same as any number multiplied by two.The card below depicts the mental image of two groups of six, or double six, that we want pupils to have. (Students who have been using ten-frames may interpret the amount as ten plus two extra.)To Learn more about strategy refer to:
https://brainly.com/question/27747591
#SPJ1
How do the coordinates of the blue point relate to the solution of the equation 3x = x + 4
Answers
we have the following:
They are related in the way taht if we replace, in both equations it gives the same result:
[tex]\begin{gathered} 3x=2\cdot3=6 \\ x+4=2+4=6 \end{gathered}[/tex]f(n) = -11 + 22(n - 1)Complete the recursive formula of f(n).f(1) = f(n) = f(n - 1) +
Answers
F(n) = -11 + 22(n-1)
[tex]\begin{gathered} f(1)\text{ implies that n=1} \\ F(1)\text{ = -11+22(1-1)} \\ f(1)=-11 \end{gathered}[/tex]Hence F(1) = -11
[tex]\begin{gathered} f(n-1)\text{ implies n=n-1} \\ f(n-1)=-11\text{ +22(n-1-1)} \\ f(n-1)=-11+22(n-2)_{} \\ =\text{ -11+22n-44} \\ f(n-1)=22n-55 \end{gathered}[/tex][tex]\begin{gathered} f(n)=\text{ -11+22(n-1)} \\ =-11+22n-22 \\ 22n-33 \\ \end{gathered}[/tex]
let An = F(n) -F(n-1)
[tex]\begin{gathered} 22n-33\text{ - (22n-55)} \\ 22n\text{ - 33-22n+55} \\ =-33+55 \\ =22 \end{gathered}[/tex]Hence F(n)= f(n-1) +22
Which one of the following angle measurements is the largest?
Answers
We have
[tex]\pi\approx3.14\text{ radians}[/tex]and
[tex]\pi=180^0[/tex]From these,
[tex]2\text{ radians<3 radians<}\pi<200^o[/tex]The largest measurement is 200 degrees. Thus, option B is correct.
A glass aquarium is in the form of a rectangular parallelepiped with dimensions 50cm by 100cm, and its depth is 30cm.How many liters of water will it hold?
Answers
Hello! To find the number of liters of water, we have to calculate the volume of the parallelepiped:
The formula of the volume is:
[tex]\begin{gathered} \text{Volume = a}\times\text{ b }\times\text{c} \\ \text{Volume = 50}\times\text{100}\times\text{30} \\ \text{Volume = }150,000\operatorname{cm}^3 \end{gathered}[/tex]Now that we know the volume, we have to convert cm³ to liters.
For this, we must remember:
1cm³ = 0.001 liter
Multiplying by rule of three, we will obtain:
[tex]\begin{gathered} 1\cdot x\text{ = 150,000 }\cdot\text{ 0.001} \\ x\text{ = 150 liters} \end{gathered}[/tex]Jamal is comparingprices of several different brandsof peanuts. Which brand is thebest buy? Explain.
Answers
So we need to figure out which is the best buy. In order to do this we must look at a particular variable: the price per ounce of peanuts. This price is given by dividing the total price of a certain amount of peanuts divided by its weight in ounces. So for the Barrel brand we get:
[tex]\frac{3.39}{10}=0.339[/tex]So the Barrel peanuts cost $0.339 per ounce. For the Mr. Nut peanuts we get:
[tex]\frac{4.54}{14}=0.324[/tex]Then the Mr. Nut peanuts cost $0.324 per ounce. Finally, the price per ounce of the Chip's peanuts is:
[tex]\frac{6.26}{18}=0.348[/tex]Then, the cheapest peanuts are those of the brand Mr. Nut and that is the best buy.
can u help me w this i got it incorrect and can’t figure out why
Answers
1) We can see here a case in which there are two secant lines coming from a single point over that circle.
2) So, we can write out the following relation
[tex]\begin{gathered} PA\cdot PB=PC\cdot PD \\ 4(4+x)=5(5+7) \\ 16+4x=25+35 \\ 16+4x=60 \\ 16-16+4x=60-16 \\ 4x=44 \\ \frac{4x}{4}=\frac{44}{4} \\ x=11 \end{gathered}[/tex]kmarks Solve the following system of equations graphically on the set of axes below 1 y 22 - 4 y = -X – 7 Plot two lines by clicking the graph. Click a line to delete il. y 10 9 8 7 6 5 4 3 2. 1 5 6 7 8 9 10
Answers
Explanation:
For the first line :
1. Draw a line which has a slope of 1 /2
2. Adjust the line so that it has a y-intercept of -4.
For the second line:
1. Draw a line which has a slope of -1
2. Adjust this line so that it has a y-intercept of -7.
Finally, find the point where the two lines intersect.
The coordinates of the point of intersection are the solution to our system.
To get a line which has a slope 1/2, you start from (0, -4 ) and then move 2 units to the right and then 1 unit up.
....................
Answers
Answer:
oop
Step-by-step explanation:
oh
Describe the translation:A) 4 units right and 6 units downB) 4 units left and 6 units upC) 6 units left and 4 units upD) 6 units right and 4 units down
Answers
To describe the transfer we will review what the points of the blue and red triangle are.
Blue triangle
I = (-2, 8)
I' = (4, 4)
First, we will determine the x-axis translation
[tex]\begin{gathered} \Delta x=x2-x1 \\ \Delta x=4-(-2) \\ \Delta x=6 \end{gathered}[/tex]6 units right
Now let's calculate the y-axis transfer
[tex]\begin{gathered} \Delta y=y2-y1 \\ \Delta y=4-8 \\ \Delta y=-4 \end{gathered}[/tex]4 units down
The answer would be 6 units right and 4 units down
A shop, had a sale.
(a) In the sale, normal prices were reduced by 15%.
The normal price of a chair was reduced in the sale by $24.
Work out the normal price of the chair.
Answers
Answer:
$160
Step-by-step explanation:
A shop, had a sale. In the sale, normal prices were reduced by 15%. The normal price of a chair was reduced in the sale by $24. Work out the normal price of the chair.
if 15% of normal price equals $24 then:
24/15% or 24/0.15 = $160 normal price
CHECK:
$160 * 0.15 = $24
Answer:
$160
Step-by-step explanation:
We want to know the price of the chair
So:
24 / 0.15 = 160$
or
24 / 15% = 160
Solve the inequality: 3x + 4 ≤ 5
Answer in interval notation.
Answers
Answer: [tex]x\leq 1/3\\[/tex]
Step-by-step explanation:
can someone please help me find the mesauser of the following?
Answers
Answer:
The measure of the given arcs are;
[tex]undefined[/tex]Given the figure in the attached image.
we want to find the measure of the given arcs.
For arc ED.
The measure of arc ED is equal to the measure of arc AB;
[tex]\begin{gathered} ED=AB=\measuredangle AOB=50^{\circ} \\ ED=50^{\circ} \end{gathered}[/tex]To get the measure of BC, we can see that AB, BC, and CD will sum up to 180 degrees.
[tex]\begin{gathered} AB+BC+CD=180^{\circ} \\ 50^{\circ}+BC+40^{\circ}=180^{\circ} \\ BC=180^0-(50^{\circ}+40^{\circ}) \\ BC=90^{\circ} \end{gathered}[/tex]To get arc BED;
[tex]\begin{gathered} \text{BED}=BE+ED \\ \text{BED}=180+50 \\ \text{BED}=230^{\circ} \end{gathered}[/tex]A boat travels 82 km on a 160 degree course. Find the distances it travel south and east, respectively
Answers
A boat travels 82 km on a 160-degree course. Find the distances it travels south and east, respectively
see the attached figure to better understand the problem
step 1
Find out the East's distance (dx)
we have that
cos(20)=dx/82
dx=82*cos(20)
dx=77.05 Kmstep 2
Find out the South's distance (dy)
sin(20)=dy/82
dy=82*sin(20)
dy=28.05 Km