$2y-y+7-1+3+7x^2-4y$

$\:2x\:-\:4\:=\:x\:+\:1$

$\left(w-r\right)^2\:=w^2-r^2$

$2\sin^2\left(z\right)-1=-\sin^4\left(z\right)+\cos^4\left(z\right)$

$m=\left(x+1\right)^2+\left(x-1\right)^2-2x^2$

$\left(-5x+10\right)\left(-5x-10\right)$

$\int\frac{18x}{\left(x-8\right)\left(x+11\right)}dx$