$\left(-5ab^2\right)\left(-2a^2b\right)$

$\frac{dy}{dx}=\frac{\left(y+3\right)\left(x-1\right)}{x\left(y-2\right)+4\left(y-2\right)}$

$3m^2-4m^2+5m^2$

$x^2y-\frac{12x}{y}$

$\left(a-\frac{1}{3}b\right).\left(a+\frac{1}{3}b\right)$

$2x^2-6x-36$

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