$\left(8+u\right)\left(8-u\right)$

$49x^6-100$

$\lim\:_{x\to\:\infty\:}\left(\frac{\sqrt{3}-\sqrt{7}}{x-7}\right)$

$4\:cos^2\left(x\right)-13\:cos\left(x\right)-12=0$

$\int_c^4\left(2x+\frac{1}{x^2}\right)dx$

$\left(4+\sqrt{x+y}-4-\sqrt{x}\right)$

$\left(-2\right)\cdot\left(-6\right)+\left(-3\right)\:\cdot10$