$\lim_{x\to-1}\left(\frac{5x^4+2x^3+2x-1}{x+1}\right)$

$2x-5=7x+10$

$\int sen^6\left(x\right)dx$

$\frac{d}{dx}\left(\frac{x}{x^2+y^2}-y^6=6\right)$

$5\cdot\left(m-4\right)=2m+3\left(m-1\right)$

$2\sin\left(x\right)^2+5\sin\left(x\right)-12=0$

$\sin^2\left(a\right)\cos^2\left(a\right)+\sin^4\left(a\right)$