$y'=-2x^3+12x^2-20x+8.5$

$\frac{ds}{dt}=20-\frac{10s}{200-2t}$

$x^2y^3z^2+xz^3+y^3=1$

$\lim_{z\to2\pi}\left(\left(z-2\pi\right)\left(\frac{z}{1-e^z}\right)\right)$

$\frac{1-\cot^2\left(x\right)}{csc^2\left(x\right)}-1$

$\frac{4}{25}x^2-\frac{4}{5}xy+y^2$

$20+90+51x$