$\left(12c^5-14d^4\right)^2$

$\left(2a^2-b\right)\left(2a^2+b\right)$

$\lim_{x\to0}\left(\frac{\left(ln\:x\right)^2}{5n}\right)$

$x^2+8x^3-10x^3$

$\left(-6a^2b^3c^6\right).\left(-3a^2b^3c^3\right)$

$\frac{a^4b^3}{a^2b}$

$\frac{2+2\tan\left(15\right)^2}{3+3\tan\left(15\right)^2}$