3,7а+2,6а-1,4в+0,4в-6,8а=-0,5а-в
3,7a+2(1,3a-0,7b)-4(-0,1b+1,7a) = 3,7a+2,6a-1,4b+0,4b-6,8a = -0,5a -b
3,7а+2,6а-1,4в+0,4в-6,8а=-0,5а-в
3,7a+2(1,3a-0,7b)-4(-0,1b+1,7a) = 3,7a+2,6a-1,4b+0,4b-6,8a = -0,5a -b