Answer:
x = -3 2/3
Explanation:
Adding the two equations gives the value of y:
(3x +7y) + (-3x -2y) = (31) + (-1)
5y = 30
y = 6
Substituting this value into the second equation, we have ...
-3x -2(6) = -1
-3x = 11 . . . . . . . . . . add 12
x = -11/3 = -3 2/3 . . divide by the coefficient of x