х:2/3 = 5/8:3
х*3 = 2/3*5/8 - свойство пропорции
х*3 = (1*5)/(3*4)
х*3 = 5/12
х = 5/12
х = 5/12:3
х = 5/12*1/3
х = 5/36
Проверка:
5/36:2/3 = 5/8:3
5/36*3/2 = 5/8*1/3.
(5*1)/(12*2) = 5/24
5/24=5/24
