2/7(1,4a-3 1/2 b)=2/7(7/5a-7/2b)=2/5a-b
1.2(5/6а-0.5b)=6/5(5/6a-5/10b)=a-3/5b
2/5a-b-a+3/5b=-3/5a-2/5b=-0.6a-0.4b
2/7(1,4a-3 1/2 b)=2/7(7/5a-7/2b)=2/5a-b
1.2(5/6а-0.5b)=6/5(5/6a-5/10b)=a-3/5b
2/5a-b-a+3/5b=-3/5a-2/5b=-0.6a-0.4b