$\left(29\right)\left(31\right)$

$2\left(9d\right)$

$\frac{d^2}{dx^2}\left(2\left(\frac{8}{5}+x^2\right)\right)$

$\int\left(\frac{2}{\left(x+1\right)\left(x^2+1\right)}\right)dx$

$\left(2a\right)\left(-2^2\right)\left(-3a^3\right)\left(4a\right)$

$18,28-17$

$\frac{2}{5}x^4-\frac{1}{2}x^3y+3x^4-y^4-0.3x^4-\frac{3}{5}x^3y-12$