$\frac{b}{\sqrt{b}-b}$

$-20ab+11+6ab$

$\int\left(12x\right)\cdot ln\left(x\right)dx$

$4y^2+36y+81$

$5x+x^2-2x+x^2$

$-\frac{1}{2}\left(0\right)^4+2\left(0\right)^2+\left(0\right)-2$

$\left[+6+9-\left(+48-65\right)-\left(-9-8\right)\right]\:-\:\left[-45\:-53-\left(+14+17\right)\right]+|+56-78|$