1.(2а-4)(5а+1) = (10a2 + 2a − 20a − 4) = 10a2 + 2a − 20a − 4 = 10a2 − 18a − 4
2.(4х+2у)(2х+3у)= (8x2 + 12xy + 4xy + 6y2) = 8x2 + 12xy + 4xy + 6y2 = 8x2 + 16xy + 6y2
1.(2а-4)(5а+1) = (10a2 + 2a − 20a − 4) = 10a2 + 2a − 20a − 4 = 10a2 − 18a − 4
2.(4х+2у)(2х+3у)= (8x2 + 12xy + 4xy + 6y2) = 8x2 + 12xy + 4xy + 6y2 = 8x2 + 16xy + 6y2