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

$2x^2+2x+1-1$

$\left(-20\right)+\:\left(1\right)\:-\:\left(-4\right)$

$\int\frac{\sin\left(x\right)^3}{\cos\left(x\right)\cdot\left(1+4\cos\left(x\right)^2\right)}dx$

$0x^2+6x^3$

$\frac{\sin\left(x\right)\cos^2\left(x\right)\csc^2\left(x\right)}{\tan^2\left(x\right)}$

$\left(-3x^6+y\right)\left(-2xy\right)$