$\int\frac{1}{\left(300-2x\right)\left(150-x\right)}dx$

$\left(1-\frac{sinx}{cosx}\right)\left(1+\frac{cosx}{sinx}\right)$

$-6+4+1$

$\int_2^3\frac{1}{x\sqrt{x^4-16}}dx$

$\int_0^{\frac{\pi}{2}}sen^3xdx$

$secxtan^2x-sec^3x\:-1$

$\:2x+5<x+9$