$5\left(-12\right)\cdot\left(-4\right)$

$\lim_{x\to3}\left(\frac{x^2-9}{3x-9}\right)$

$\frac{1}{5}m^2n-\frac{2}{3}mn-\frac{3}{2}m^2n+\frac{3}{10}m^2n-\frac{8}{3}mn$

$\frac{d^2}{d^2x}\left(x^2y^2-2x=1\right)$

$\frac{105x^9+49x^8}{7x^4}$

$\left(22.3\right).\left(\frac{1}{13.4}\right).\left(\frac{2.00}{1}\right)$

$\int_1^{\infty}\cos\left(x\right)^2dx$