$\int\left(\frac{8x+9}{\left(8x^2+18x\right)^4}\right)dx$

$\cot^2\left(x\right)\cdot\sin\left(x\right)\cdot\sec^2\left(x\right)$

$\left(5a\left(x+7\right)+4ay\right)$

$5x^3-x$

$\int\:\frac{2\left(x+3\right)}{e^x}dx$

$\int ( 3 x - 5 ) ^ { 3 } 3 d x$

$-\cot b+\cos b=0$