b, H ( x ) = x^3-2x^2+x-1/2 - ( x^3 + x^2 + 2 ) = x^3 - 2x^2 + x - 1/2 - x^3 - x^2 - 2
= ( x^3 - x^3 ) - ( 2x^2 + x^2 ) + x - ( 1/2 + 2 ) = x^2 + x - 5/2
c, R(x) = 2x^3 - x + ( x^3-2x^2+x-1/2 )= 2x^3 - x + x^3-2x^2+x-1/2 = ( 2x^3 + x^3 ) - 2x^2 - (x - x ) - 1/2 = 3x^3 - 2x^2 - 1/2