$\frac{2cot\left(x\right)-sec\left(x\right)csc\left(x\right)}{sec\left(x\right)+csc\left(x\right)}$

$-2x+4x-5+4-6x$

$5\:sen3x\:-\:2\:=\:-4sen3x\:$

$\left(csc\left(x\right)\right)^2=\frac{1}{4}$

$\int\left(\frac{\cos\left(\sqrt[3]{x}\right)}{x}\right)dx$

$\left(-x^3y^2\right)\left(2x^5y^3\right)$

$\frac{1}{a+7}=\frac{-5a}{5a}$