$49x^2y^8-x^2y^3$

$-4\left(1\right)\left(-14\right)$

$f\left(x\right)=\frac{3x}{\left(1+x^2\right)^2}$

$\int x\left(3x^3-x^-2-6\sqrt{x}\:+4\:\right)dx$

$25x^2+40x+64$

$\left(e^{2x}+2e^x\right)\cdot\sqrt{y}\cdot\frac{dy}{dx}=y^2\cdot\left(e^x+1\right)$

$\lim_{x\to0}\left(\frac{3^x-1}{\sin\left(x\right)}\right)$