Решите уравнения: 1-x=1/5 x+2/7=1 1-x=4/7

1 - x = 1/5;

- х = 1/5 - 1;

- х = 1/5 - 5/5;

- х = - 4/5;

- х * (-1) = - 4/5 * (-1);

х = 4/5;

1 - 4/5 = 1/5;

5/5 - 4/5 = 1/5;

1/5 = 1/5.

x + 2/7 = 1;

х = 1 - 2/7;

х = 7/7 - 2/7;

х = 5/7;

5/7 + 2/7 = 1;

7/7 = 1;

1 = 1.

1 - x = 4/7;

- х = 4/7 - 1;

- х = 4/7 - 7/7;

- х = - 3/7;

- х * (-1) = - 3/7 * (-1);

х = 3/7;

1 - 3/7 = 4/7;

7/7 - 3/7 = 4/7;

4/7 = 4/7.