$\left(\frac{a^{4}}{b^{3}}\right)^{5}\left(\frac{b^{4}}{a^{6}}\right)^{4}$

$b^2-8b+15$

$\lim_{x\to-2}\left(\frac{\left(2x+12-2x^2\right)}{\sqrt[3]{x+2}}\right)$

$y-xy=y^2e^y\frac{dx}{dy}$

$-2a^3\left(3+2xy-5ax^2\right)$

$\left(x^2+y^2\right)\left(x^2-y^2\right)^2$

$2x^2-2x>0$