բ) 4(x-y)+7(x-y)=4x-4y+7x-7y=11x-11y

դ) 2a-3(b-a)=2a-3b+3a=5a-3b

զ) a(x-y)-b(x+y)=ax-ay-bx-y

ը) 2ab(a+2b)-3ab²(a-4)=2a²b+4ab²-3a²b²+7ab²

բ) a(b+c-bc)-b(c+a-ac)+c(b-a)=ab+ac-abc-bc-ab+abc+cb-ca=0