$\frac{dx}{dy}=\frac{1+x^2}{1+y^2}$

$\left(\frac{\frac{1}{2}^2}{\frac{1}{2}3}.\frac{1}{\frac{2}{\frac{1}{2}^2}}^{10}\right)^2$

$\left(x+3y+4\right)^2$

$\frac{a^{12}-125b^{12}}{a^6-b^6}$

$5\cdot1.5$

$\frac{3\left(x^2-\frac{4}{5}\right)}{8}+\frac{\left(x^2-\frac{4}{5}\right)}{4}=2$

$16x^4-9y^4$