13/21 -(X - 2 5/7)= 3/14
13/21 -X + 2 5/7= 3/14
-х=3/14-2 5/7-13/21
-х=9/42-2 30/42-26/42
-х=-2 47/42=-3 5/42
Х=3 5/42
13/21 -(X - 2 5/7)= 3/14
13/21 -X + 2 5/7= 3/14
-х=3/14-2 5/7-13/21
-х=9/42-2 30/42-26/42
-х=-2 47/42=-3 5/42
Х=3 5/42