2x = 5y + 8. (1st)
3x + 2y = 31 so 3x = -2y + 31 (2nd)
multiply (1st equation) by 3 and (2nd equation) by 2
6x = 15y + 24
6x = -4y + 62
-----------------------subtract
0 = 19y - 38
19y = 38
y = 2
2x = 5y + 8
2x = 5(2) + 8
2x = 18
x = 9
answer
solution (9, 2)