$-18-\left(-7\right)$

$\lim_{x\to0}\left(\frac{\left(1+x\right)^2-\left(1+6x\right)}{x^2+x^7}\right)$

$\left(x+7\right)\left(x+5\right)\left(x-2\right)$

$\int\frac{1+\sqrt{1-x^2}}{\sqrt{1-x^2}}dx$

$\int14x^{-2}dx$

$\int\left(\frac{\left(9x-1\right)}{\left(x-9\right)\left(x-8\right)^2}\right)dx$

$\left(6c^2b^2-7\right)\left(3c^2b^2+3\right)$