$\lim_{x\to-\infty}\left(\frac{\sqrt{2x^6-2x^2}}{-x^2+2x-4}\right)$

$\left(x+2y\right)dx=2xdy$

$\int\frac{5}{\left(x+3\right)\left(x-3\right)}dx$

$\left(3\right)\left(x+4\right)\left(x-5\right)\left(x+5\right)$

$12,23\cdot23,24$

$\left(7x^5-10\right)\left(7x^5+10\right)$

$\tan^2\left(\infty\right)\cdot\left(1-\sin^2\left(\infty\right)\right)=\sin^2\left(\infty\right)$