$\frac{\left(-2xy^2\right)\left(5x^{2y}\right)}{\left(5y^2\right)\left(-4x^5\right)}$

$2x-50<4x-800$

$\lim_{x\to\infty}\left(\frac{\sin6x}{\sin5x}\right)$

$x^2+7xy+0y^2+6x+28y+8$

$\lim_{x\to0}\left(e^x-3x\right)^{\frac{2}{x}}$

$\lim_{x\to0}\left(\frac{\cos\left(x\right)-1}{3\left(x\right)^2\csc^2x}\right)$

$\frac{tan\:\left(x\right)-cot\:\left(x\right)}{tan\:\left(x\right)+cot\:\left(x\right)}=1-2cos^2\left(x\right)$