$\left(\frac{a}{6}+\frac{x^3}{b}\right)\left(\frac{a}{6}-\frac{x^3}{5}\right)$

$\int_{-\infty}^1\sqrt{6-y}dy$

$5^x-a^y^2\:10x^2$

$\sqrt{x}\left(6-x^6\right)$

$\lim_{n\to0}\left(\frac{\left(n+1\right)^{n+1}x}{n^n}\right)$

$\left(\sqrt{a}\:+\:2x\right)^2$

$4x^4-20x^2y+25y^2$