Question

Which of the following (x,y) pairs is the solution for the system of equations x + 2y = 2 and -2x

+y = 16?

Answer 1

(-6,4)

Explanation:

make sure x's or y's are the same and opposite signs

x + 2y = 2 and -2x +y = 16

multiply 2 with x + 2y = 2 so that there is 2x

2 * (x + 2y = 2) = 2x + 4y = 4

2x + 4y = 4

-2x +y = 16

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5y = 20

y = 4

put y = 4 back into one of the equations

-2x +y = 16

-2x + 4 = 16

-2x = 12

x = -6