What is the product in simplest form? State any restrictions on the variable.

z squared over z plus one times z squared plus three z plus two over z squared plus three z

The product in the simplest form is

(z^2(z^2 + 3z + 2))/(z(z + 1)(z + 3))

Restrictions on the variable: The variable z cannot be equal to 0, -1, or -3, as it would result in division by zero.