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3 years ago

Solve the system of equations 7x+10y=36 y=2x+9

Mathematics

1 answer:

Damm [24]3 years ago

5 0

Answer:

x = -2

y = 5

Step-by-step explanation:

Given two equations

1. 7x + 10y = 36

2. y = 2x + 9

Substitute 2x + 9 for y in equation 1.

We have

7x + 10y = 36

7x + 10(2x + 9) = 36

Distribute 10 into (2x + 9)

We have

7x + 10 x 2x + 10 x 9 = 36

7x + 20x + 90 = 36

27x + 90 = 36

Subtract 90 from both sides to eliminate 90 on the left side

27x + 90 - 90 = 36 - 90

27x = -54

Divide both sides by 27 to isolate x

27x/27 = -54/27

x = -2

Now substitute -2 into either equation to get y

Using equation 2, we have

y = 2x + 9

= 2 x -2 + 9

= -4 + 9

= 5

x = -2

y = 5

Check

7(-2) + 10(5) = 36

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