9514 1404 393
Answer:
(x, y) = (80, -68)
Explanation:
Subtract the second equation from the first.
(3x +y) -(x +y) = (172) -(12)
2x = 160 . . . . . . . . . simplify
x = 80 . . . . . . . . . divide by 2
y = 12 -x = 12 -80 = -68 . . . . . find y from the second equation
The solution is (x, y) = (80, -68).