`P= 8x^3 -4x^2 +2x+1+x^3+x^2-x+1`
`P=9x^3 -3x^2+x+2`
\(\text{ P = (2x-1).4x^2+2x+1+(x+1)x^2-x+1}\)
\(\text{P =}\) \(\text{[(2x-1) . 4x^2 ]}\)\(\text{[(x+1) .x^2]}\)
\(\text{P = }\) \(\text{8x^3 - 4x^2 + 2x^3 + 2x^2 + 2x + 1 + x^3 - x + 1}\)
\(\text{P =}\) \(\text{(8x^3 + 2x^3 + x^3) + (-4x^2 + 2x^2) + (2x - x) + (1 + 1)}\)
\(\text{P =}\) \(\text{11x^3 - 2x^2 + x + 2}\)