В уравнении x+1/7-2/7+4/7 х равен 1, 3/7, 5/7
1+1/7-2/7+4/7=10/7=1 3/7 3/7+1/7-2/7+4/7 =3/7 5/7+1/7-2/7+4/7=8/7=1 1/7