*Answer*
x+0 or x=-0.63297
heres step by step
−5x=(−4x2−2x)(−x2−9)−5x=4x4+2x3+36x2+18x
heres step by step
Step 1: Subtract 4x^4+2x^3+36x^2+18x from both sides
−5x−(4x4+2x3+36x2+18x)=4x4+2x3+36x2+18x−(4x4+2x3+36x2+18x)−4x4−2x3−36x2−23x=0
Step 2: Factor left side of equation
x(−4x3−2x2−36x−23)=0Step 3: Set factors equal to 0.x=0 or −4x3−2x2−36x−23=0x=0 or x=−0.63297