3/4
Пошаговое объяснение:
(1/3 + 1/5 + 1/6)x = 21/40
(10/30 + 6/30 + 5/30)x = 21/40
21/30 x = 21/40
x = 21/40 * 30/21
x = 3/4
3/4
Пошаговое объяснение:
(1/3 + 1/5 + 1/6)x = 21/40
(10/30 + 6/30 + 5/30)x = 21/40
21/30 x = 21/40
x = 21/40 * 30/21
x = 3/4