For the system of equations below, is the graphing method or the
substitution method the better method for solving? Why?

y=2⁢x+6

y=−9⁢x−1
​

Aldo and Leola would put 9 fiction books and 18 nonfiction books on each of the 7 bookshelves, for a total of 189 books on the shelves. They would then put the remaining 7 books on Ms. Krebs's desk.

To represent the problem as an equation, we first need to define some variables. Let's let "f" represent the number of fiction books, and "n" represent the number of nonfiction books. We know from the problem that there are 2 times as many nonfiction books as fiction books, so we can write:

n = 2f

We also know that they put the same number of books on each of the 7 bookshelves and put as many as they can on each shelf. Let's call this number "s". We can then write an equation for the total number of books that can fit on the bookshelves:

7s = f + n

Since n = 2f, we can substitute 2f for n in the equation:

7s = f + 2f

Simplifying, we get:

7s = 3f

Finally, we know that any remaining books are put on Ms. Krebs's desk. Let's call this number "r". We can write an equation for the total number of books:

f + n = 7s + r

Substituting 2f for n, we get:

f + 2f = 7s + r

Simplifying, we get:

3f = 7s + r

Now we can solve for "f":

3f = 7s + r

f = (7s + r) / 3

We don't have enough information to solve for "s" or "r", but we can use this equation to find the number of fiction books. For example, if we know that there are a total of 70 books, we can write:

f + n = 70

f + 2f = 70

3f = 70

f = 23.33

Since we can't have a fractional number of books, we would round down to the nearest whole number and get:

f = 23

We could then use the equation f = (7s + r) / 3 to find the number of books on each shelf, assuming there are no books left over:

23 = (7s + 0) / 3

69 = 7s

s = 9.86

Since we can't have a fractional number of books on a shelf, we would round down to the nearest whole number and get:

s = 9

So Aldo and Leola would put 9 fiction books and 18 nonfiction books on each of the 7 bookshelves, for a total of 189 books on the shelves. They would then put the remaining 7 books on Ms. Krebs's desk.

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The volume of the snowball is decreasing at a rate of approximately 108π cubic centimeters per minute when the radius is 9 cm.

The volume V of a sphere with radius r is given by the formula V = (4/3)πr^3. To find the rate at which the volume is changing with respect to time, we need to take the derivative of V with respect to time t. Using the chain rule, we get:

dV/dt = (dV/dr) * (dr/dt)

Since the radius is changing at a constant rate, we can calculate dr/dt by dividing the change in radius by the time interval:

dr/dt = (10 cm - 20 cm) / (30 minutes) = -1/3 cm/min

To find dV/dr, we can take the derivative of the volume formula with respect to r:

dV/dr = 4πr^2

Substituting the given radius of 9 cm, we get:

dV/dr = 4π(9)^2 = 324π cm^2

Finally, we can substitute these values into the formula for dV/dt:

dV/dt = (dV/dr) * (dr/dt) = 324π cm^2 * (-1/3 cm/min) = -108π cm^3/min

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Answer:

x = 26.

Step-by-step explanation:

Given: 2x + 3x + 50 = 180

First, write it down:

2x + 3x + 50 = 180

Then, collect like terms:

2x + 3x = 180 - 50

Then calculate:

5x = 130  (Divide both sides by 5)

x = 26

The best interpretation of the interval is: We are 95% confident that the mean time for response is between 2.8 minutes and 12.3 minutes. Option D is correct

A confidence interval is a measure of how accurately an estimate (such as the sample average) corresponds to the actual population parameter. It is a range of values that the researcher believes is very likely to include the actual value of the population parameter.

Here, a 95 percent confidence interval for the mean time, in minutes, for a volunteer fire company to respond to emergency incidents is determined to be (2.8. 12.3). Thus, we can say that we are 95% confident that the mean time for response is between 2.8 minutes and 12.3 minutes. Therefore, option D is correct.

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Answer:

Area: 81*pi

Circumference: 18*pi

Step-by-step explanation:

Area: 9^2= 81

So it would be 81*pi

Circumference: 9*2= 18

So it would be 18*pi

If you want the full area then it's 81*pi= 254.34

If you want the full circumference it's 18*pi= 56.55

to find 7/8 of 3.5, we multiplied 7/8 and 3.5 together to get 49/16, which we then converted to a mixed number in the simplest form, giving us the answer of 3 1/16.

To find 7/8 of 3.5, we can simply multiply 7/8 and 3.5 together.

7/8 x 3.5 = (7/8) x (7/2) = 49/16

So, the answer is 49/16. However, we need to write the answer as a mixed number in the simplest form.

To convert an improper fraction to a mixed number, we need to divide the numerator by the denominator. In this case, 49 divided by 16 is 3 with a remainder of 1.

So, the mixed number is 3 1/16.

To simplify the mixed number, we need to check if we can reduce the fraction part (1/16) further. 1 is not divisible by any number other than 1 itself, so it is already in its simplest form.

Therefore, the final answer is 3 1/16.

In summary, to find 7/8 of 3.5, we multiplied 7/8 and 3.5 together to get 49/16, which we then converted to a mixed number in the simplest form, giving us the answer of 3 1/16.

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The length of the side EF is equal to 18 units since the triangle DEF and triangle ABC are similar and DEF is bigger than ABC in the margin of 3 times.

Given, two triangles ABC and DEF.

The length of AB = 8 units

The length of its concurrent side DE = 24 units

Also given that the length of BC = 6 units

Here we can see that:

As both triangles are similar, their corresponding sides are in proportion.

This means that:

[tex]\frac{BC}{EF} = \frac{AE}{DE} =\frac{AC}{DF}[/tex]

Length of AB * 3 = Length of DE

Now the length of the side EF will be 3 times more than the side BC.

Length of EF = Length of BC * 3

Length of EF = 6 * 3

Length of EF = 18 units.

Therefore, the length of the side EF is equal to 18 units.

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Using expressions,

4a. x= 0 is not possible.

4b. x= 1 is not possible.

5a. (9x-5)(9x+5)

5b. (x-3)(2x+1)

6. 1/(3x-7)

7a. x = (-5,∞)

7b. x = (∞,2]

7c. x = (-3,7]

A mathematical expression is a phrase that has a minimum of two numbers or variables and at least one mathematical operation.

Let's examine the writing of expressions.

The other number is x, and a number is 6 greater than half of it.

As a mathematical expression, this proposition is denoted by the expression x/2 + 6.

Here the values of x has to be such that the denominator is not equal to zero.

So, x cannot be zero and x cannot be 1 as these two values in the respective questions will make the denominator zero.

a. 81x²-25

= 81x² + 45x-45x-25

=9x(9x+5)-5(9x+5)

= (9x-5)(9x+5)

b. 2x²-5x-3

= 2x² + x - 6x -3

= x(2x+1)-3(2x+1)

=(x-3)(2x+1)

Next, the intervals for x are as follows:

x = (-5,∞)

x = (∞,2]

x = (-3,7]

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Answer:Hence, Nathan rode 2 miles

Step-by-step explanation:ask if you need any questions

The company's total income, expenditure and profit is given respectively as follows:

a.) £180

b.) £146

C.) £34

To calculate the profit of the company the formula such as given below is used.

Profit = total income - total expenditure

The total income = 25+20+35+100 = £180

The total expenditure = 110+20+6+10 = £146

Profit = 180-146 = £34

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The amount of the mark up is $66 and the selling price is $286.

The amount by which a product's cost is raised to determine its selling price is known as the markup percentage. Usually, it is represented as a percentage of the item's price. Markup percentage is determined by the following equation:

Markup percentage = (Selling price - Cost price) / Cost price x 100%

Given that, the mark up is 30%.

Thus,

Mark up = 0.3 x $220 = $66

The selling price is:

Selling price = $220 + $66 = $286

Hence, the amount of the mark up is $66 and the selling price is $286.

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Hence, the value of  variable in the given expression x is 8

An angle is formed when two straight lines  meet at a common endpoint.

∠1 = 7x - 4

∠2 = 3x + 28

A secant line that crosses two parallel lines produces these angles. After that, these angles were congruent, which means that their measures are equal.

Then, equaling  both given expressions and solving for x,  we get:

Step1: subtract 3x both sides

7x - 4 = 3x + 28

Step2: add 4 both sides

7x - 3x - 4 = 28

Step2: simplify like terms

7x - 3x = 28 + 4  

Step3: divide by 4 both sides

4x = 32  

x = 32/4

x = 8

Hence, the value of x is 8.

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Answer:

4m^2+15-5m

Step-by-step explanation:

Remove parentheses.

4m^2-5-5m+20

Collect like terms.

4m^2+(-5+20)-5m

Simplify

4m^2+15-5m

To calculate the monthly periodic interest rate from an annual percentage rate (APR), we need to divide the APR by 12 (the number of months in a year). We can use the following formula:

Monthly periodic interest rate = APR / 12

In this case, the APR is 16.75%, so we can plug it into the formula and simplify:

Monthly periodic interest rate = 16.75% / 12

Monthly periodic interest rate = 1.395833...%

Rounding to the nearest hundredth of a percent, we get:

Monthly periodic interest rate = 1.40%

Therefore, the monthly periodic interest rate for the primary credit card holder is 1.40%.

fv(40,20) ≈ (f(40.1,20) - f(40,20))/0.1 , ft(40,20) ≈ (f(40,20.05) - f(40,20))/0.05 are the required functional estimations of a given representations.

However, we can estimate the partial derivatives with respect to x (fv) and y (ft) at the point (40,20) using the definition of partial derivatives:

fv = ∂f/∂x ≈ (f(40+h,20) - f(40,20))/h

where h is a small increment in the x direction. Similarly,

ft = ∂f/∂y ≈ (f(40,20+k) - f(40,20))/k

where k is a small increment in the y direction.

To estimate fv(40,20) and ft(40,20), we need to choose small values of h and k and evaluate the function at the corresponding points. Let's say h = 0.1 and k = 0.05:

fv(40,20) ≈ (f(40.1,20) - f(40,20))/0.1

ft(40,20) ≈ (f(40,20.05) - f(40,20))/0.05

We can then use these estimates to approximate the value of f(40.1,20.05) using the first-order Taylor approximation:

f(40.1,20.05) ≈ f(40,20) + fv(40,20)0.1 + ft(40,20)0.05

Note that this is an approximation and may not be very accurate if the function is highly nonlinear or has discontinuities. However, it can give us a rough idea of the value of f(40,20) and how it changes with small variations in x and y.

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A sample size of at least 61 should be taken to obtain a margin of error of 0.04 for the estimation of a population proportion at a 95% confidence level.

Given data:

To determine the sample size required for estimating a population proportion with a given margin of error at a 95% confidence level, you can use the following formula:

[tex]n=\frac{Z^2 \cdot p(1-p)}{E^2}[/tex]

n is the required sample size.

Z is the Z-score corresponding to the desired confidence level. For a 95% confidence level, the Z-score is approximately 1.96.

p is an estimate of the population proportion (since you don't have prior data, you can use p =0.5  for maximum variability, which results in the largest sample size requirement).

E is the desired margin of error, which is 0.04 in this case.

Substitute the values into the formula:

[tex]n=\frac{1.96^2*0.5^2}{0.04^2}[/tex]

The value of n = 60.26

Since the sample size is a whole number, n = 61

Hence, a sample size of at least 61 should be taken for the estimation of a population proportion at a 95% confidence level.

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The key features of the function are Base = 0.72, Rate = decrement and it decays

Given that

y = 3000 * (0.72)ˣ

The given equation is in the form of exponential decay:

Base: The base of the exponential function is the constant term that is being raised to a power. In this case, the base is 0.72.

Rate of change: The rate of change is the factor by which the function is being multiplied or divided as the input variable increases.

Since the base is less than 1, the function is decreasing as x increases. The rate of decrease is given by the base, which is 0.72.

Growth or decay: As the base is less than 1, the function is decreasing, which means it is a decay function.

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Men will have completed oil changes in hours Therefore, Will and Gabriel will each have done 12 oil changes after 4 hours.

Hours is a unit of time measurement. It is used to measure a specific amount of time and is usually denoted by the symbol “h”. There are 24 hours in a day, 60 minutes in an hour and 60 seconds in a minute. Hours are used to measure both short and long periods of time. Commonly, hours are used to measure the length of a workday, the length of a school day, or the length of a movie. Hours are also used to measure how long a person has been alive, how long an event has been going on, or how long an item has been in use.

Let W be the total number of oil changes Will has completed, and G be the total number of oil changes Gabriel has completed.

System of equations:

W = 8 + 2t

G = 3t

Since they will be tied at some point during the day, W = G.

Substituting W into G's equation:

8 + 2t = 3t

Solving for t:

2t = 8

t = 4

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Answer:

See below!

Step-by-step explanation:

a) 1, 2, 3, 4, 5

The possible outcomes are all the options that there are on the spinner

b) 2

There are only 2 even numbers!

c) [tex]\frac{2}{5}[/tex] or 0.4

There are 2 out of 5 numbers are even on the spinner so that must be the solution!

d) 1

The spinner has only one multiple of 3, so the possible outcome should also be 1.

e) [tex]\frac{1}{5}[/tex] or 0.2

There are only 1 out of 5 options which are multiples of 3, so that would be our solution

f) 4

There are 4 prime numbers in the spinner (1, 2, 3, 5), so that would be a possible outcome.

g) [tex]\frac{4}{5}[/tex] or 0.8

The spinner has 4 out of 5 prime numbers, so our answer would be that!

Hope this helps, have a lovely day! :)

The probability that when he enters the restaurant today it will be at least 5 minutes until he is served is  0.2676 and probability that average time until he is served in eight randomly selected visits is 0.0409.

The square root of the variance is used to calculate the standard deviation, a statistic that expresses how widely distributed a dataset is in relation to its mean. By calculating the deviation of each data point from the mean, the standard deviation can be calculated as the square root of variance.

Given that mean μ = 4.2 , standard deviation σ = 1.3

1. P(X >= 5) = P((X - μ)/σ >

                    = (5 - 4.2) /1.3

                    = P(Z ≥ 0.6154)

                    = 1 - P(Z < 0.6154)

                    = 1 - 0.7324

                    = 0.2676

The required probability is 0.2676.

2.Given that n = 8 then  [tex]\bar x[/tex] = σ/[tex]\sqrt{(n)[/tex]  = 1.3/√(8) = 0.4596

P(x-bar ≥ 5) = P(([tex]\bar x[/tex] - μ)/σx-bar ≥ (5 - 4.2)/0.4596)

                        = P(Z ≥ 1.7406)

                        = 1 - P(Z < 1.7406)

                        = 1 - 0.9591

                        = 0.0409

The required probability is 0.0409.

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If the objective function coefficient for variable 1 decreases by 20, the solution will shift in the direction of the decrease in the objective function coefficient. It means that the optimal solution that was obtained previously will no longer remain optimal, and the new optimal solution will be found with the new objective function coefficient.

In linear programming, the objective function determines the maximum or minimum value that can be attained in the solution, subject to the constraints. The constraints in the problem can be either equalities or inequalities, which limit the range of values that the decision variables can take on.

The change in the objective function coefficient will change the direction of the optimal solution, and it may affect the feasibility of the solution. It means that some constraints may no longer be satisfied, or some variables may become infeasible.

In such cases, it will be necessary to revise the constraints or the variables to ensure the feasibility of the solution.

The solution can also be affected if the constraints of the problem change. The new constraints may limit the range of values that the variables can take on, or they may add new variables to the problem. These changes can affect the feasibility of the solution, and it may require the problem to be solved again to obtain the new optimal solution.


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Answer:

The line y = 2 - 5/20 can be simplified to y = 2 - 1/4 = 7/4.

Substituting y = 7/4 into the equation of the circle, we get:

(x - 5)² + (7/4 + 1)² = 25

(x - 5)² + (15/4)² = 25

(x - 5)² = 25 - (15/4)²

x - 5 = ±√(25 - (15/4)²)

x = 5 ± √(25 - (15/4)²)

Simplifying, we get:

x = 5 ± √(400/16 - 225/16)

x = 5 ± √(175/16)

x = 5 ± (√175)/4

Therefore, the two intersection points are:

Left point: (5 - (√175)/4, 7/4)

Right point: (5 + (√175)/4, 7/4)

The sum of the matrices A and C from the list of options is the matrix B

Given the following matrices

Matrix A

| 0  6  2 |

| 1  5  -2 |

Matrix C

| -2  5  3 |

| -1  -7  3|

To find the sum of matrices A and C, we add the corresponding elements in each matrix:

So, we have: A + C

| 0 - 2  6 + 5  2 + 3 |

| 1 - 1    5 - 7  -2 + 3|

Evaluate the sum

| -2  11  5 |

| 0   -2  1 |

This represents option B

Therefore, the sum of matrices A and C is (B)

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Complete question

What is the sum of A+C?

Matrix A

| 0  6  2 |

| 1  5  -2 |

Matrix C

| -2  5  3 |

| -1  -7  3|

In the given triangle, the value of x = 5.

What is a triangle's definition?

A triangle is a geometrical shape that is defined as a polygon with three sides and three angles. It is a closed figure with three line segments as its sides, and these sides intersect at three points, which are called vertices. When we add all the angles of a triangle then the result will always be 180°.

Now,

As we know the property of a triangle that

sum of all angles of triangle=180°

given angles are (9x-1)°, 74° and 62°

then,

        9x-1+74+62=180°

9x+135=180

9x=45

x=5

Hence,

           the value of x is 5.

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Answer:  ^4√11^5 = 11^(5/4)

Step-by-step explanation: When we apply a radical, we are asking what number, when raised to a certain power, gives us the number under the radical. For example, ^4√16 is asking what number, when raised to the fourth power, gives us 16. The answer is 2, since 2^4 = 16.

So, ^4√11^5 is asking what number, when raised to the fourth power, gives us 11^5. We can simplify this expression using the exponent laws:

^4√11^5 = (11^5)^(1/4) = 11^(5/4)

Therefore, the simplified expression for ^4√11^5 is 11^(5/4). This expression does not have any radicals, making it easier to work with and manipulate.

Hope this helps, and have a great day!

The linear measure of arc KML on OO is approximately 3.33 units, rounded to two decimal places.

Since KM is a diameter, angle KOM is a right angle. Therefore, angle KOL is a straight angle, which means that angle MOL is 180 - 145 = 35 degrees.

Now, we can use the fact that the measure of an arc is proportional to the measure of the angle it subtends. In particular, if the measure of an angle in degrees is θ and the radius of the circle is r, then the length of the arc it subtends is given by:

length of arc = (θ/360) * 2πr

In this case, the radius of the circle is half of the diameter KM, which is 36/2 = 18. So we have:

length of arc KML = (35/360) * 2 * 3.14 * 18

≈ 3.33

Therefore, the linear measure of arc KML on OO is approximately 3.33 units, rounded to two decimal places.

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Answer:

The shape of each cut surface is a rectangle. The dimensions of the first cut surface are 8 inches by 10 inches, and the dimensions of the second cut surface are 10 inches by 20 inches.

The area of the first cut surface is 8 inches x 10 inches = 80 square inches. The area of the second cut surface is 10 inches x 20 inches = 200 square inches.

To find the total area Jenny needs to paint, we need to add the area of the first cut surface to the area of the second cut surface.

Total area = Area of first cut surface + Area of second cut surface

Total area = 80 square inches + 200 square inches

Total area = 280 square inches

Therefore, Jenny needs to paint a total area of 280 square inches.

The graph for the linear equation y=24x, will be a straight line having coordinate (1,24) i.e. B.

What is a linear equation, exactly?

A linear equation is a first-degree algebraic equation in which each term is either a constant or the product of a constant and a single variable (degree 1). A linear equation is stated as y = mx + b, where y is the dependent variable, x is the independent variable, m is the line's slope, and b= y-intercept .

A linear equation's graph is a straight line. The line's slope decides how steep it is, and the y-intercept indicates where the line crosses the y-axis. Linear equations are used to model relationships between variables that are directly proportional to each other, such as distance and time, or cost and quantity.

Now,

Given equation is y=24x

then for  x,    y is

              1,    24

              2,   48

              3,    72

              4,     96

Hence, the graph will be as represented in option 2.

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