Direct-substituting x = -2 gives 0/0, so we know that by the factor theorem, both the numerator and denominator have a factor of x + 2. From there, we can cancel out the conflicting factors and apply the limit.
We can factor the numerator and denominator to get:
x^3 - x^2 - x + 10 = (x + 2)(x^2 - 3x + 5)
x^2 + 3x + 2 = (x + 2)(x + 1).
So we have:
lim (x-->-2) (x^3 - x^2 - x + 10)/(x^2 + 3x + 2)
= lim (x-->-2) [(x + 2)(x^2 - 3x + 5)]/[(x + 2)(x + 1)]
= lim (x-->-2) (x^2 - 3x + 5)/(x + 1), by canceling out x + 2
= [2^2 - 3(-2) + 5]/(-2 + 1)
= (4 + 6 + 5)/(-1)
= -15.
I hope this helps!