4 5/7-(x-6 3/7) = 2 6/7
-(х-6 3/7) = 2 6/7 - 4 5/7
-х +6 3/7 = -(4 5/7 - 2 6/7)
-х = -1 6/7 - 6 3/7
-х = -(1 6/7 + 6 3/7)
-х= - 8 2/7
х= 8 2/7
ответ: 8 2/7