You can check the answer to any "solving" problem by plugging it back in to the original exercise. In your case, plug in your values for "x" and "y", and see if they work:

. . . . .-3[-3] - 2[-3] = 9 + 6 = 15 (yes!)

. . . . .-9[-3] + 8[-3] = 27 - 24 = 3 (yes!)

Since your solution values "check", your answer must be correct.

Good work!

P.S.Thank youfor showing all your work!!