Well 12 = 3×4 thus answer would be -3 and -4
For algebra solution, we can let smallest integer be n then that would be n(n+1) = 12, so we can go ahead and solve for n:
n(n+1) = 12
n² + n - 12 = 0
(n-3)(n+4) = 0
n = 3 or -4
Since we need negative integers, n would be -4 and then next integer (n+1) would be -3.
Hope this helps.
