Here's another way to do it, by dividing directly with long division: ax2+ bx+ (-8+a) x2+0x-1)ax4+bx3- 8x2+ 6x- 6 ax4+0x3- ax2 bx3+(-8+a)x2+ 6x bx3+ 0x2- bx (-8+a)x2+ (6+b)x- 6 (-8+a)x2+ 0x- (-8+a) (6+b)x+(-6+(-8+a)) For this remainder to be 2x+1, 6+b = 2 -6+(-8+a) = 1 b = -4 -6-8+a = 1 -14+a = 1 a = 15 Edwin