$18a^2b^2+12a^2b+30ab^2$

$\lim_{x\to0}\left(\frac{x^2sin\left(\frac{1}{x}\right)}{x}\right)$

$\left(5a^3+y^2\right)\left(5x^3+y^2\right)$

$\lim_{x\to\pi}\left(\frac{sinx-1}{tan\left(2x\right)}\right)$

$\frac{x}{4}+\frac{x}{6}+\frac{x}{18}=17$

$2+\left|-6\right|$

$u^2+14u+49$