$\left(x+y\right)\:x\:\left(x-y\right)$

$\frac{\tan\left(x\right)}{1+\sec\left(x\right)}=\csc\left(x\right)-\cot\left(x\right)$

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

$20+90+51mnuv$

$3\left(-9q+9\right)+3\left(8q-3\right)$

$\frac{2x^3+6xy^2}{x^2+3y^2}$

$-67-\left(98-12\right)$