$\int\frac{e^x-e^{-x}}{e^x-e^{-x}}\:dx$

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

$\int\frac{e^x-2}{e^x+2}dx$

$\frac{8x^3+27y^3}{3x}$

$\frac{\sin\left(-a\right)}{\sin\left(a\right)}\:+\frac{\cos\left(-a\right)}{\cos\left(a\right)}$

$\frac{-2}{-x\left(x+2\right)}=\frac{x+3}{x+2}$

$\left(a+4b+5c\right)^2$