Find D when 8x^3-12x^2-2x+D is divided by 2x+1 when the remainder is -2

8x³-12x²-2x+D...(1)

2x+1...(2)

Assume 2x+1=0 so x=-1/2

8x³-12x²-2x+D=-2... when divided by (2)

substitute -1/2 into all X values

rearrange to find D