m(x)=x^2+4x (mn)(x)= x^2+4x(x) (x^2+4x)(x) COMPLETE Which is equal to: x^3+4x^2 5x^2 4x^4 COMPLETE n(x)=x Evaluate (mn)(x) for x=-3 (mn)(-3)=

To evaluate $(mn)(x)$ for $x=-3$, we first need to find the product of the functions $m(x)$ and $n(x)$.<br /><br />Given:<br />$m(x) = x^2 + 4x$<br />$n(x) = x$<br /><br />The product of $m(x)$ and $n(x)$ is:<br />$(mn)(x) = (x^2 + 4x)(x)$<br /><br />Now, let's substitute $x=-3$ into the expression:<br />$(mn)(-3) = ((-3)^2 + 4(-3))(-3)$<br />$(mn)(-3) = (9 - 12)(-3)$<br />$(mn)(-3) = (-3)(-3)$<br />$(mn)(-3) = 9$<br /><br />Therefore, $(mn)(-3) = 9$.