Выполните действие (1: 12+1: 6): ( 3: 8-1: 4) ; ( 1-4: 9): (1: 3-1: 4). (7: 9-2: 3): (1: 3+2: 15) ..

(1/12 + 1/6) :(3/8-1/4) = (3/12):1/8 = 4 : 1\8 = 4 * 8 = 32
( 1-4:9):(1:3-1:4) = 5/9 : 1/12 = 5/9 * 12 = 20/3 = 6* 1/3
(7:9-2:3):(1:3+2:15) = 1/9 : 7/15 = 1/9 *15/7 = 5/21