7/8 - х=3 1/21 + 13/14
7/8-х=3 2/42 +39/42
7/8-х=3 41/42
х=7/8-3 41/42 х= 147/168 - 3 164/168= -3 17/168
7/8 - х=3 1/21 + 13/14
7/8-х=3 2/42 +39/42
7/8-х=3 41/42
х=7/8-3 41/42 х= 147/168 - 3 164/168= -3 17/168