$\frac{x^{3}-2x^{2}+x-12}{x+3}$

$\frac{dy}{dx}=\frac{y}{x}+2x+7$

$\frac{\cos\left(x\right)}{1}+\frac{\cos\left(x\right)}{\sin\left(x\right)}$

$\lim_{x\to\infty}\left(\frac{x-8}{x}\right)^{\frac{x}{4}}$

$\frac{d^2y}{dx^2}=-x^2$

$2a+7a-a$

$\left(-12\right)\left(-6-10\right)$