Answer:
(x, y) = (-3, 3)
Explanation:
You can add these two equations together to cancel the x terms:
(3x +2y) +(-3x +y) = (-3) +(12)
3y = 9 . . . . . . . . simplify
y = 3 . . . . . . . . . divide by 3
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Substituting for y in the second equation gives ...
-3x +3 = 12
-3x = 9 . . . . . subtract 3
x = -3 . . . . . . divide by -3
The solution is (x, y) = (-3, 3).
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The solution can be found quickly and easily using a graphing calculator.