$15a^2b^4cd+16a^2b^9$

$\lim_{x\to+\infty}\left(\frac{\sqrt{3x^2+2x+1}}{2x+7}\right)$

$\int21z^3e^zdz$

$\frac{dy}{dt}=\frac{t^{3}}{\sqrt{t+3}}$

$\sin\left(x\right)^3+\sin\left(x\right)\cos\left(x\right)^2$

$\int\left(z^3\left(6z^4+1\right)\right)dx$

$\int_{-\pi}^{\pi}\left(sen\left(x\right)\cdot\left(3+cos\left(x\right)\right)\right)dx$