$-20a+45a$

$\int\frac{6}{\left(x^{-6}e^{2x}\right)}\:dx$

$\frac{2x-1}{3}\:\ge\:-6x+10$

$\left(5u+7u^2\right)^3$

$\lim_{x\to0}\left(\frac{6x^2+e^{-4x}-2}{-8x^2+x}\right)$

$\int_0^{\infty}\left(\frac{x^2}{a^2+x^2}\right)dx$

$\int_{-5}^{\sqrt{x}}\left(\frac{cost}{t}\right)dt$