$\frac{\sin\left(x\right)\cdot\cos\left(x\right)}{1-2\cos\left(x\right)}=\frac{1}{\tan\left(x\right)-\cot\left(x\right)}$

$8-2x<3\left(x+1\right)$

$c^2+c+c$

$\int_1^{\infty}\left(e^{-ux}\right)dx$

$\left(x+6\right)\cdot3$

$\frac{9x^2-2x+16}{x^2}$

$a\left(x\right)=x^2+3x-10$