Let's solve your equation step-by-step
-9x^3-72x^2-96x=36=3x^3=x^2-3x=8
Step 1: Subtract 3x^3+x^2-3x+8 from both sides.
-9x^3-72x^2-96x+36-(3x^3+x^2-3x+8)=3x^3+x^2-3x+8(3x^3+x^2-3x+8)
-12x^3-73x^2-93x+28=0
Step 2: Factor left side of equation.
(-4x+1)(x+4)(3x+7)=0
Step 3: Set factors equal to 0.
-4x+1=0 or x+4=0 or 3x+7=0
x=1/4 or x=-4 or x=-7/3 (these are not division btw idk how to add the factor stuff)
answer is x=1/4 or x=-4 or x=-7/3
