$4x^2-y^2\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:$

$\frac{m}{m+5}+\frac{10m}{m^2-25}$

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

$14z-9y+7x-4x-2y-6z$

$1-\left(-10\right)$

$\left(2x^3\:+\:5x\:-\:3\right)\left(4x\:-\:3x^2\:+\:2x^3\right)$

$\frac{243x^5-1024y^{10}}{4x+4y^2}$