$2\left(x-6\right)\left(x+3\right)-4\left(x^2-x+1\right)\left(x-6\right)+3\left(x-5\right)\left(x^2+1\right)$

$\lim\:_{x\to\:0}\left(\frac{ln\left(x^2+2x\right)}{lnx}\right)dx$

$3x\ge-\frac{2}{3}$

$\int\left(7x^{-3}+10x^{-\frac{1}{2}}+8x^{\frac{2}{5}}\right)dx$

$\frac{x+7}{x-8}\le3$

$4x^2-49$

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