1 способ:
6 1/5 - (2 3/5 + х) = 3 2/5,
6 1/5 - 2 3/5 - х = 3 2/5,
-х = 3 2/5 - 6 1/5 + 2 3/5,
-х = (3 - 6 + 2) + (2/5 - 1/5 + 3/5),
-х = -1 + 4/5,
-х = -5/5 + 4/5,
-х = -1/5,
х = 1/5,
2 способ:
6 1/5 - (2 3/5 + х) = 3 2/5,
2 3/5 + х = 6 1/5 - 3 2/5,
2 3/5 + х = 5 6/5 - 3 2/5,
2 3/5 + х = 2 4/5,
х = 2 4/5 - 2 3/5,
х = 1/5