Stella

I assume you want to expand this?

(-x^2)*(x^3+3/2x+1)

$(-x^2)*(x^3+\frac{3}{2}x+1)$

Muliply each term in the second bracket by -x^2

$=(-x^2)*(x^3)\quad+\quad (-x^2)* (\frac{3}{2}x)\quad +\quad (-x^2)* (1)$

now simplify each term separately.