2/7x+3/7x равно 2 7/14

Решим заданное уравнение:

2/7 х + 3/7 х = 2 7/14;

х * (2/7 + 3/7) = 2 7/14;

х * ((2 + 3) / 7) = 2 7/14;

х * 5/7 = 2 7/14;

х = 2 7/14 : 5/7;

х = (2 * 14 + 7) / 14 : 5/7;

х = (28 + 7) / 15 : 5/7;

х = 35/15 : 5/7;

х = 35/15 * 7/5;

х = (35 * 7) / (15 * 5);

х = (5 * 7 * 7) / (15 * 5);

х = (7 * 7) / 15;

х = 49/15;

х = 3 (49 - 3 * 15) / 15;

х = 3 (49 - 45) / 15;

х = 3 4/15.

Ответ: х = 3 4/15.

Решим подобное уравнение:

2/5 х + 1/5 х = 1 1/15;

(2 + 1) / 5 х = 1 1/15;

3/5 х = 1 1/15;

х = 1 1/15 : 3/5

х = (1 * 15 + 1) / 15 * 5/3;

х = 16/15 * 5/3;

х = (16 * 5) / (5 * 3 * 3);

х = 16/9;

х = 1 7/9.

Ответ: х = 1 7/9.