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

$\left(7x^3+4y^2\right)\left(7x^2-4y^2\right)$

$49+84x$

$\int\left(\frac{1}{x^2\left(16x^2-9\right)}\right)dx$

$4p+5p-7p$

$10\cdot sin\left(x\right)-15\cdot cos\left(2\cdot x\right)$

$2\left(x^2-2x\right)$