Х (y-z) - (-y+z)

2b (x-y) - (y-x)

5 (c-b) - (ab-ac)

2 (x-c) - (-bx+bc)

х (y-z) - (-y+z) = х (y-z) + (y-z) = (y-z) (x+1)

2b (x-y) - (y-x) = 2b (x-y) + (x-y) = (x-y) (2b+1)

5 (c-b) - (ab-ac) = 5 (c-b) + a (c-b) = (c-b) (5+a)

2 (x-c) - (-bx+bc) = 2 (x-c) + b (x-c) = (x-c) (2+b)