$tan\left(x-\frac{3\pi}{4}\right)=\frac{tanx+1}{1-tanx}$

$3xy^5-12xy^4+3xy$

$\frac{x^2-x-2}{x^2-7x-8}$

$2\tan\left(x\right)\cos^2\left(x\right)-1=0$

$\left(2y+12\right)\left(2y-5\right)$

$5\left(3n+2\right)+8n\left(-2n+1\right)$

$9\cdot\left(\left(-3\right)\right)+4-\left(-2^2\right)$