$-\left|6\right|+\left|-14\right|-20$

$\left(-x^4+y^4\right)\cdot\left(\:2x+y\right)$

$\left(3-2y^2\right)^2$

$\lim_{x\to1}\left(\frac{ln\left(x\right)^3}{6sin\left(\pi x\right)}\right)$

$\lim_{x\to\infty}\left(\frac{8+e^x}{8x}\right)$

$-31x^2+220x-204$

$\int\:\frac{x^3}{\sqrt[3]{x^2+1}}\:dx$