$\lim_{xy\to\infty}\left(\frac{x^3-2x^2+xy^2-2y^2}{x^2+y^2}\right)$

$\left(5x+4y\right)\left(5x+2y\right)$

$\left(x^3y^3-6\right)\left(9x^3y^3+8\right)$

$\left(a+2b+7c\right)^2$

$\int sec^2\left(7x+9\right)dx$

$\frac{dy}{dx}=\ln\left(x\right)\cdot\sqrt{16-y^2}$

$\sqrt{100x^4}y^8z^{12}$