$cos\left(x\right)-sin\left(x\right)=\sqrt{2}cos\left(\frac{\pi}{4}+x\right)$

$\left(m-n+8\right)\cdot\left(m-n-3\right)$

$\frac{3}{9x^3}$

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

$x^2-26x=-15$

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

$1>x-1$