$\int3x^3cos\left(2x\right)dx$

$a+1\:x\:a+2$

$\frac{1}{2}\cdot\:\log\:_{27}\left(5c+6\right)=\frac{2}{3}$

$\lim_{x\to0}\left(\frac{2-2\cos\left(x\right)-\frac{1}{2}x^2}{2x^3}\right)$

$15=3.5$

$\lim_{x\to\infty}\left(\frac{9x^4+9x^2}{3x^4+10}\right)$

$\frac{x^4-9x^2-x+2}{x^2+9}$