a, ax – bx + ab – x 2 = (ax -x2)+(ab-bx) = x(a-x)+b(a-x)=(a-x)(x+b)
b) ax – ay – bx + by + (x – y)2 = (ax-ay)-(bx-by)+(x-y)2=a(x-y)-b(x-y)+(x-y)2= (x-y)3(a-b+1) = (x-y)(x-y)(x-y)(a-b+1)
c) 3a(2x – 1) + (2a + 3)(2x – 1) - 2(1 – 2x) = 3a(2x – 1) + (2a + 3)(2x – 1)+2(2x+1)
=(2x-1)(3a+2a+3-2)=(2x-1)(5a+1)
d) 2x(a – b – c) + 4xy(b + c - a) + 6x2= 2x(a – b – c)-4xy(a-b-c)=(a – b – c)(2x-4xy)