$\lim_{x\to+\infty}\left(\frac{x+4}{e^x}\right)$

$\frac{x^2-3x-10}{x^2-4}$

$\lim_{x\to6}\:\left(y-5\right)\left(y-7\right)$

$5x^3y^4\cdot\:2x^{-4}y^3$

$\left(a+b\right)\left(ab+b^2\right)=a^3+b^3$

$\int\frac{9}{5}\:\left(3x+1\right)^2dx$

$\lim_{h\to0}\left(\frac{x^2h+3xh+h^3}{2xh+5h^2}\right)$