Please assist with this question . Will give brainliest. No links please!!!

Answer:
[tex]-16x^3+9x^2[/tex]
Step-by-step explanation:
[tex]-4x^3-12x^3+9x^2[/tex]
[tex](-4-12)x^3+9x^2[/tex]
[tex]-16x^3+9x^2[/tex]