(3 1/8 + 1 3/4) х = 2 1/6
(25/8+7/4)х=13/6
(25/8+14/8)х=13/6
39/8х=13/6
х=13/6 : 39/8
х=13/6* 8/39
х=1/3*4/3
х=4/9
проверка
39/8 * 4/9= 13/6
156/72=13/6
2 12/72=13/6
2 1/6= 2 1/6
3 1/8x + 1 3/4x = 2 1/6
3 1/8x + 1 6/8x = 2 1/6
4 7/8x = 2 1/6 | : 4 7/8
x = 4/9
