Выполните действия 1) (1/12+1/6):(3/8-1/4); 2) (1-4/9):(1/3-1/4); 3) (1/3-5/16):(1/6-1/8); 4) (5/7-2/3):(4/9-5/12);

(1/12 + 1/6) : (3/8 - 1/4) = (1/12 + 2/12) : (3/8 - 2/8) = 3/12 : 1/8 = 1/4 * 8/1 = 8/4 = 2;

(1 - 4/9) : (1/3 - 1/4) = (9/9 - 4/9) : (4/12 - 3/12) = 5/9 : 1/12 = 5/9 * 12/1 = 60/9 = 20/3 =

 = 6 2/3;

(1/3 - 5/16) : (1/6 - 1/8) = (16/48 - 15/48) : (4/24 - 3/24) = 1/48 : 1/24 = 1/48 * 24/1 = 24/48 =

= 1/2;

(5/7 - 2/3) : (4/9 - 5/12) = (15/21 - 14/21) : (16/36 - 15/36) = 1/21 : 1/36 = 1/21 * 36/1 =

= 36/21 = 12/7 = 1 5/7;