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11. Use elimination to solve the system of equations given by 10x - 4y = -20 and 10x - 5y = 35.

1 Answer

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Answer:

x = -24; y = -55

Explanation:

Step 1: Multiply the first equation by -1:

Multiplying the first equation by -1 will allow to to eliminate the xs since -10x - 10x = 0:

-1(10x - 4y = -20)

-10x + 4y = 20

Step 2: Add -10x + 4y = 20 and 10x - 5y = 35 to eliminate the xs and solve for y:

Solving for y:

-10x + 4y = 20

+

10x - 5y = 35

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(-10x + 10x) + (4y - 5y) = (20 + 35)

(-y = 55) / -1

y = -55

Thus, y = -55.

Step 3: Solve for x by plugging in -55 for y in the first equation (10x - 4y = -20):

Solving for x:

10x - 4(-55) = -20

(10x + 220 = -20) - 220

(10x = -240) / 10

x = -24

Thus, x = -24.

User Jakub Czaplicki
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