$\left(3\sqrt{5}\right)\left(2\sqrt{5}\right)$

$\lim_{x\to0}\left(\frac{7x^4+2x^2}{3x^4+19}\right)$

$\frac{d^5}{dx^5}\tan\left(x\right)$

$\infty^3-\infty^2$

$\frac{d}{dy}\left(x=80\cdot e^{\frac{y}{15}}\right)$

$\left(\frac{2}{3}x-\frac{3}{5}y\right)^3$

$-1-\left(-1\right)+\left(-1\right)-\left(-1\right)+0-\left(-1\right)$