$x^2+3x-4\cdot x^2+4x-5$

$t+20t+0$

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

$\sqrt{9-3\cos^2}$

$12m^2n\left(1+2mn+3m^2n^2\right)$

$\frac{1}{x-4}+\frac{x}{x-2}-\frac{x}{x^2-6x+8}$

$\left(9.8\right)\left(20\right)\left(150\right)$