$e=\frac{\left(a+b\right)^2\text{sen}90^{\circ}-\left(a-b\right)^2\cos180^{\circ}}{\csc90^{\circ}+\text{sec}0^{\circ}}$

$\frac{4x^2+26x+32}{x-5}$

$\frac{1}{4}x^2-5x$

$\frac{\left(x+a\right)^5-a^5}{\left(x+a\right)-a}$

$cos90$

$-\cos a-11=2\cos a-9$

$\sec\left(x\right)^2-\frac{13}{30}=\frac{1}{\sin\left(x\right)^2\cdot\cos\left(x\right)^2}$