359. Multiply: $2 x^{3}-4 x^{2}+3 x$ and $2 x^{4}+3 x^{3}$.

Examples of multiplication and division of polynomials.
359. $4 x^{7}-2 x^{6}-6 x^{5}+9 x^{4}$. 360. 1) $\frac{6 x^{3}}{y^{2} z^{3}}$; 2) $3 x^{2} y z^{2}$.