$\frac { 64 - s ^ { 2 } } { 8 - s }$

$2^{\frac{3}{3}}$

$15+\left|15\cdot4-3\cdot\left(7-3\right)\right|-9$

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

$\frac{x^3+0-8}{2x^2}$

$\lim_{x\to4}\left(\frac{4x+16}{x^2+16}\right)$

$\int\left(5x^3-6x^2-8\right)\left(3x^{-2}-9x^{-1}\right)dx$