(x^2-25)/(x^2+7x+10) What is the first step to solving this?
$$\\\frac{(x^2-25)}{(x^2+7x+10)}\\\\ =\frac{(x-5)(x+5)}{(x+5)(x+2)}\\\\ x\ne-2\qquad and \qquad x\ne -5\\\\ =\frac{x-5}{x+2}\\\\$$