a) x3 - x2 - x + 1
= x2.(x - 1) - (x - 1)
= (x - 1).(x2 - 1)
= (x - 1).(x - 1).(x + 1)
= (x - 1)2.(x + 1)
b) 3x2 - 3xy + 5y - 5x
= 3x.(x - y) - 5.(x - y)
= (x - y).(3x - 5)
c) x3 - 7x - 6
= x3 - 4x - 3x - 6
= x.(x2 - 4) - 3.(x + 2)
= x.(x - 2).(x + 2) - 3.(x + 2)
= (x + 2).[x.(x - 2) - 3]
= (x + 2).(x2 - 2x - 3)
= (x + 2).(x2 - 3x + x - 3)
= (x + 2).[x.(x - 3) + (x - 3)]
= (x + 2).(x - 3).(x + 1)
a, x^3 - x^2 - x + 1
= x^2 (x-1) - (x-1)
= (x^2 -1) (x-1)
b, 3x^2 - 3xy + 5y - 5x
= 3x(x-y) - 5(x-y)
= (3x - 5) (x-y)
a, x3-x2-x+1=(x3-x2)-(x-1)=x2(x-1)-(x-1)=(x-1)(x2-1)=(x-1)(x+1)(x-1)=(x+1)(x-1)2