$\frac{3x^6+x^4-x^2-3}{x+1}$

$\left(-25\right)\cdot\left(+40\right)\cdot0$

$6x^{-4}$

$\frac{x^3-5x^2+3}{x^3}$

$\lim_{x\to0}\left(\frac{\left(e\right)^x-1+\ln\left(1-x\right)}{\tan\left(x\right)-x}\right)$

$\frac{\csc^2a-\sin^2a}{\csc^2a\left(2-\cos^2a\right)}$

$\lim_{x\to0}\left(\frac{7\:in\left(2x\right)}{in\left(x\right)}\right)$