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2 years ago

A collection of 108 coins containing only quarters and nickels is worth $21 wich value could replace q on the chart?

Mathematics

2 answers:

Greeley [361]2 years ago

5 0

Answer:

There would be 30 nickels and 78 quarters.

Step-by-step explanation:

To find this, start by creating a system of equations in which x is the number of nickels and y is the number of quarters. Make the first equation the total number of coins.

x + y = 108

Make the second equation based on the value.

.05x + .25y = 21

Now multiply the second equation by -4 and add together to get the y value to cancel.

x + y = 108

-.2x - y = -84

--------------------

.8x = 24

x = 30

Now use this value to find y.

x + y = 108

30 + y = 108

y = 78

Makovka662 [10]2 years ago

5 0

Answer:

There would be 30 nickels and 78 quarters.

Step-by-step explanation:

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Plz help ill give brainliest

horrorfan [7]

Answer:

Step-by-step explanation:

Cone

Givens

r = 1.5 inches

h = 4 inches

Formula

V = 1/3 pi r^2 h

V = 1/3 3.14 * 1.5^2 * 4

V = 1/3* 3.14 * 2.25 * 4

V = 9.42

Semi sphere

Givens

r = 1.5

Formula

V = 2/3 * pi * r^3

Solution

V = 2/3 * 3.14 * 1.^3

V = 7.065

Total

V = 9.42 + 7.065

V = 16.485

Rounded to the nearest 1/100

V = 16.49

Answer

First left column = 0

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8 0

2 years ago

PLEASE HELP 20 POINTS solve the system of equations y=-5x-7 and -4x-3y=-1 by substitution.

Ainat [17]

Answer:

Solution: x = -2; y = 3 or (-2, 3)

Step-by-step explanation:

Equation 1: y = -5x - 7

Equation 2: -4x - 3y = -1

Substitute the value of y in Equation 1 into the Equation 2:

-4x - 3(-5x - 7) = -1

-4x +15x + 21 = -1

Combine like terms:

11x + 21 = - 1

Subtract 21 from both sides:

11x + 21 - 21 = - 1 - 21

11x = -22

Divide both sides by 11 to solve for x:

11x/11 = -22/11

x = -2

Now that we have the value for x, substitute x = 2 into Equation 2 to solve for y:

-4x - 3y = -1

-4(-2) - 3y = -1

8 - 3y = -1

Subtract 8 from both sides:

8 - 8 - 3y = -1 - 8

-3y = -9

Divide both sides by -3 to solve for y:

-3y/-3 = -9/-3

y = 3

Therefore, the solution to the given systems of linear equations is:

x = -2; y = 3 or (-2, 3)

Please mark my answers as the Brainliest if you find this helpful :)

7 0

2 years ago

Can someone answer part B for me? Thank you and will give brainliest.

frez [133]

Answer:

The answer to part B is B.

Step-by-step explanation:

Could you take another photo so I can see the bottom of the page?

4 0

3 years ago

Find the dimensions of the rectangle with area 256 square inches that has minimum perimeter, and then find the minimum perimeter

mezya [45]

Answer:

Dimensions: $A=a\cdot b=256$

Perimiter: $P=2a+2b$

Minimum perimeter: [16,16]

Step-by-step explanation:

This is a problem of optimization with constraints.

We can define the rectangle with two sides of size "a" and two sides of size "b".

The area of the rectangle can be defined then as:

$A=a\cdot b=256$

This is the constraint.

To simplify and as we have only one constraint and two variables, we can express a in function of b as:

$b=\frac{256}{a}$

The function we want to optimize is the diameter.

We can express the diameter as:

$P=2a+2b=2a+2*\frac{256}{a}$

To optimize we can derive the function and equal to zero.

$dP/da=2+2\cdot (-1)\cdot\frac{256}{a^2}=0\\\\\frac{512}{a^2}=2\\\\a=\sqrt{512/2}= \sqrt {256} =16\\\\b=256/a=256/16=16$

The minimum perimiter happens when both sides are of size 16 (a square).

4 0

2 years ago

Carolina goes to a paintball field that charges an entrance fee of \$18$18dollar sign, 18 and \$0.08$0.08dollar sign, 0, point,

FromTheMoon [43]

Answer: At least 713 paintballs

Step-by-step explanation:

Based on the information that has been given in the question, the inequality that'll be used to solve the question will be:

18+0.08B≥75

0.08B≥75-18

0.08B≥57

B≥57/0.08

B≥712.5

Carolina needs to buy at least 713 paintballs along with the entrance fee to get the promotion.

4 0

3 years ago

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