$18-\frac{\left(3^2-1\right)}{\left(3+1\right)}$

$\left(\frac{5}{6}m^4+\frac{4}{3}n^3\right)\left(\frac{5}{6}m^4-\frac{4}{3}n^3\right)$

$3\tan\left(x\right)-\sqrt{3}=0$

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

$\left(6a+13\right)^2$

$\frac{d}{dx}2\sqrt{x}+\sqrt{y}$

$7\left(3f\:+\:4\right)\:+\:\left(9\right)$