Answer
$\dfrac{x}{3}; x\ne -2$
Work Step by Step
Factor the numerator and the denominator completely to obtain:
$=\dfrac{4x(x+2)}{12(x+2)}
\\=\dfrac{4x(x+2)}{4(3)(x+2)}$
Cancel the common factors to obtain:
$\require{cancel}
\\=\dfrac{\cancel{4}x\cancel{(x+2)}}{\cancel{4}(3)\cancel{(x+2)}}
\\=\dfrac{x}{3}; x\ne -2$
($x$ cannot be $-2$ because it will make the original expression undefined.)
