1.7(4а+6)-12а=28а+42-12а=16а+42
2. 8х-4(16-2х)=8х-64+8х=16х-64=16(х-4)
3. 1.7(а-4)+0.6(6-2а)=1.7а-6.8+3.6-1.2а=0.5а-3.2
4. 1.5(8х-6у)-(5у-3х)*2.4=12х-9у-(12у-7,2х)=12х-9у-12у+7.2х=19.2х-21у
5. -(4.3-2.4)-(5.8-2.6х)=-4.3х+2.4-5.8+2.6х=-1.7-3.4=-2(х+1.7)