Question

Find the solution of the system of equations below using the linear combination method: 4x+9y=28 -4x-y=28

Answer 1

x = -35/4, y= 7

Explanation:

4x+9y=28

-4x-y=28

Add the equations together

4x+9y=28

-4x-y=28

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8y = 56

Divide by 8

8y/8 = 56/8

y = 7

Now we can find x

4x +9y = 28

4x +9(7) = 28

4x +63 = 28

Subtract 63 from each side

4x+63-63= 28-63

4x =-35

Divide each side by 4

4x/4 = -35/4

x = -35/4