2/3m+1/4a -1/4m+1/2a=8/12m+1/4a-3/12a+2/4a=3/4a+5/12m
0,2(7а -6b) - 0,3(3а - 4b)=1.4a-1.2b-0.9a+1.2b=0.5a
2/3m+1/4a -1/4m+1/2a=8/12m+1/4a-3/12a+2/4a=3/4a+5/12m
0,2(7а -6b) - 0,3(3а - 4b)=1.4a-1.2b-0.9a+1.2b=0.5a