|4x+3|=9+2x if we square both sides, we can eliminate the absolute values signs...
16x^2+24x+9=81+36x+4x^2 subtract the right side from both sides
12x^2-12x-72=0 now we can factor
12(x^2-x-6)=0
12(x^2+2x-3x-6)=0
12(x(x+2)-3(x+2)=0
12(x-3)(x+2)
So:
x= -2 or 3