Question

a(b-c)-(c-b)
A(2+b)-(c-b)
5x-5y-ax+ay

Answer 1

a(b-c)-(c-b)=ab-ac-c+b
a(2+b)-(c-b)=2a+ab-c+b
5x-5y-ax+ay=5(x-y)-a(x-y)=(x-y)(5-a)