Answer:
x = -4
Step-by-step explanation:
The solution to a "sum and difference" system of equations can be found by adding the equations together.
(x +y) +(x -y) = (-10) +(2)
2x = -8 . . . . . . simplify
x = -4 . . . . . . . divide by 2
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Additional comment
y = -6, though this question did not ask that value.
