$\left(a^2\right)\left(3a^{x-2}-2a^{x-1}a^x\right)$

$9xy^2+3xy-6x^2y$

$\lim_{t\to4}\left(\frac{t^3+64}{t+4}\right)$

$\int\frac{1}{\left(4x^2+25\right)^2}dx$

$-\frac{\sqrt[3]{x^4}}{6}$

$\frac{dy}{dx}=\frac{\pi\left(1+y^2\right)x}{12\sqrt{1+x^2}}$

$\:4h\:-\:8h\:-\:2h$