Chapter 13 - Section 13.1 - Finding Limits Numerically and Graphically - 13.1 Exercises - Page 905: 12

$\frac{4}{3}$

$\lim _{x\rightarrow -2}\dfrac {x^{2}-4}{x^{2}+x-2}=\dfrac {\left( x-2\right) \left( x+2\right) }{x^{2}-4+x+2}=\dfrac {\left( x-2\right) \left( x+2\right) }{\left( x+2\right) \left( x-2\right) +x+2}=\dfrac {\left( x+2\right) \left( x-2\right) }{\left( x+2\right) \left( x-1\right) }=\dfrac {\left( x-2\right) }{x-1}=\dfrac {-4}{-3}=\dfrac {4}{3}$