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Rus_ich [418]
2 years ago
6

X + 7y = 21 x + 4y = 15 Solve the simultaneous equations

Mathematics
2 answers:
Mariulka [41]2 years ago
8 0

<u>Answer</u>:

x = 7, y = 2

<u>Explanation</u>:

equations given:

x + 7y = 21

x + 4y = 15

make "x" the subject:

x + 7y = 21

x = 21 - 7y .........equation 1

x + 4y = 15

x = 15 - 4y .......equation 2

Solving both the equations simultaneously:

15 - 4y = 21 - 7y

-4y + 7y = 21 - 15

3y = 6

y = 6 ÷ 3

y = 2

If y is 2

Then x = 21 -7y;

x = 21 - 7(2)

x = 21 - 14

x = 7

Yuliya22 [10]2 years ago
6 0

x + 7y= 21

7 goes to RHS = X+ y = 21/7-3

x + 4y = 15

4 goes to RHS= x+y = 15/4 = 3.75

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Answer: when x = 7, y = 16

Step-by-step explanation: Here, we know that y varies inversely as x.

When we have two sets of inversely related coordinates, x₁ and y₁,

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<h2>x₁ y₁ = x₂ y₂</h2><h2 />

Here, we know that y = 14 when x = 8 so

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We want to know the value of y when x = 7.

So our other coordinates will be 7 and y.

So we have (8)(14) = (7)(y).

Simplifying, (8)(14) is equal to 112 and (7)(y) is equal to 7y.

So we have 112 = 7y.

Now we simply solve for y by dividing both sides of the equation by 7.

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on the left, 112 divided by 7 is equal to 16.

So we have 16 = y.

So when x is equal to 7, y is equal to 16.

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Step-by-step explanation:

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At the local grocery store, a 16-ounce bottle of apple juice costs $3.20. What is the cost of the apple juice per ounce? Show wo
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<u>The answer is $0.20</u>

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