D. -4/3
Let's solve your equation step-by-step.
9x2+24x+20=4
Step 1: Subtract 4 from both sides.
9x2+24x+20−4=4−4
9x2+24x+16=0
Step 2: Factor left side of equation.
(3x+4)(3x+4)=0
Step 3: Set factors equal to 0.
3x+4=0 or 3x+4=0
x=
−4
/3
Hope This helps
Dodecahedron is a 3D shape, usually when it ends with hedron it is 3D.