Решыте 0,9n-0.8m-0.7m+3.5n-1.9n=?
0,9n-0.8m-0.7m+3.5n-1.9n=2.5n-1.5m
0,9n-0.8m-0.7m+3.5n-1.9n=2,5n-1.5m=5( 0.5n-0.3m)