$\int_0^{2\pi}\left(-4cosxsenx\right)dx$

$\lim_{x\to+0}\left(\frac{1}{x^9}-\frac{1}{x^5}\right)$

$\log\left(x+4\right)-\log\left(x-2\right)=\log\left(3\right)$

$\lim_{y\to2}\left(\frac{y^2-4}{y-2}\right)$

$\left(7y+x+2\right)dx=\left(5y+3x+6\right)dx$

$\int\left(x+3\right)\left(x-1\right)^3dx$

$\cos\left(2x\right)cscx+cotg\:x\:=0$