$\int\frac{x^3}{\left(x^2+9a^2\right)^{\frac{3}{2}}}dx$

$\lim_{x\to0}\left(\frac{2\:sen\:\left(\pi x\right)\:+\:\left(x^2\:-\:1\right)}{\left(1-x\right)^2}\right)$

$7x^2-14$

$\left(\frac{5}{3}\cdot21\right)+455$

$2x^2+3+2\sqrt{6x}$

$-16x^2+32x+4=0$

$4-\left(1-3\right)$