Question

i’ve tried to do it but i’m confused and need someone to show me.

Answer 1

From the given question,

$x^4+9x^2$

Now,

Put x=-3 into the given expression

$x^4+9x^2=(-3)^4+9(-3)^2$$\begin{gathered} x^4+9x^2=(-3)^4+9(-3)^2 \\ =81+9(9) \\ =81+81 \\ =162 \end{gathered}$

Hence, the option D is correct.