$\left(-3ab^2\right)\left(-2a^2b^4c\right)\left(2abc\right)$

$-15+1b$

$\lim_{x\to2}\left(\frac{\sin\left(2x+x^2\right)}{\sin\left(4-x^2\right)}\right)$

$2ab+ab$

$\frac{x^3+7x^2+4x-12}{x+6}$

$\int_0^1\left(8x+x-x\right)dx$

$\int\left(w-2w^3\right)cos\left(w^2-w^4\right)dx$