Multiply $\frac{\left(x-1\right)\left(x+2\right)^{2}}{x+3}$ times $\frac{x+3}{x+2}$ by multiplying numerator times numerator and denominator times denominator.
Multiply $\frac{\left(x-1\right)\left(x+2\right)^{2}}{x+3}$ times $\frac{x+3}{x+2}$ by multiplying numerator times numerator and denominator times denominator.