1,5a + 9,7b + 5,8a - 1,3b = 12,75a + 1,85b - 9,55a +3,5b =
(1,5а+5,8а)+(9,7б-1,3б)=7,3а+8,4б (12,75а-9,55а)+(1,85б+8,4б)=3,2а+10,25б