= (x - x2 )(4-3x) - (3x2 +5x - 12x - 20)
= 4x - 4x2 - 3x2 + 3x3 -3x2 - 5x + 12x + 20
= 3x3 - 10x + 11x +20
e)
= x.x-x.1 .(4-3x) - (x-4)(3x+5)
= x2 - x(4 - 3x) - ( x-4 )(3x+5)
= x2(4 -3x) - x ( 3x- 5) -4( 3x- 5)
= 4x2- 3x3 - 3x2 + 5x - 12x + 20
= - 3x3 + 4x2 - 3x2 + 5x - 12x + 20
= - 3x3 + x2 - 7x + 20