$\frac{3}{1}a^2\:\cdot\:\frac{1}{3}\:x^6$

$4x^2-12x+9^7$

$\sqrt{\frac{\left(x^2-1\right)}{\left(x^2+1\right)}}$

$\int\frac{5x-3}{\left(x-1\right)\left(x-3\right)}dx$

$\lim_{x\to0}\left(\frac{\sin\left(3x\right)+ax+bx^3}{2x^3}\right)$

$\int\:\frac{\ln\:y}{y^2}dy$

$16\left(m-n\right)^2-40\left(m-n\right)\left(m+2n\right)+25\left(m+2n\right)^2$