$\left(-7\right)+\left(-7\right)+\left(-7\right)+\left(-7\right)+\left(-7\right)+\left(-7\right)$

$2\left(5-8f\right)$

$sen^2x\left(ctgx-cscx\right)\frac{1}{\sin\left(x\right)\cdot\cos\left(x\right)^2}$

$\frac{x^2-5x+1}{x^2-4x+3}$

$\left(6x+2y-z+7\right)+\left(5y-2x+4z\right)-\:\left(3x-4y+3z-9\right)$

$-\frac{\left(n+2\right)\left(-\frac{x}{9}\right)^n\left(n+1\right)}{729}$

$\int7e^{\cos\left(x\right)}\sin\left(x\right)dx$