2(a-b)+a(a-b)= 7(x+y)-a(x+y)= 2(a-b)+c(b-a)= 2a(b-3)-5c(3-b)= (m+1)-m(m+1)= x(y-z)²+(z-y)²= 4(m+n)+(m+n)= 2(x-y)-a(x-y)=
1) 2a-2b+a^2-ab 2) 7x+7y-ax-ay 3) 2a-2b+cb-ca 4) 2ab-6-15 c-5cb 1)(m+1)-(m^2-1 )= (m+1)-(m-1)(m+1)=m-1