$7x^5y^5\left(14x^4y^2\right)$

$2x^2-20x+42=0$

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

$\left(5x^2+3x-5\right)^2$

$\int\left(3x+4\right)e^{-5x}dx$

$\int\frac{\sqrt{x^2-9}}{3\cdot x}dx$

$\frac{\sec\left(x\right)}{1-\cos^2\left(x\right)}=\cos\left(x\right)$