$sec\:\left(x\right)^2\:-\:cos\:\left(x\right)^2\left(sec\left(x\right)^2\right)$

$50+2x<6x$

$\lim_{x\to\infty}\left(1-\frac{4}{x}\right)^{1.3x}$

$\lim_{x\to2}\left(\frac{\sqrt{\left(x^2-5x+6\right)^3}}{x-2}\right)$

$\left(7q+5\right)^2$

$\int_1^3\frac{e^u}{x^2}dx$

$18x^3-38x^2$