$-0.8\cdot1.8\cdot\left(-0.5\right)$

$\frac{\left(4a^4b^4+36x^6\right)}{2a^2b^2+64x^3}$

$5a^3b-3a^5b^2+7ab^3$

$\int\left(\frac{3cosx}{sen^3x}\right)dx$

$7u+3u$

$-\left(-8\right)+9-\left(-8\right)+\left(-14\right)-\left(20\right)$

$\int\left(\frac{2}{y\left(4-y\right)}\right)dx$