Выполните действие: 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) (1\12 + 1\6) : (3/8 - 1/4) =
(1/12+2/12):(6/16-4/16)=
1/4:1/8=1/4*8/1=2

2) (1 - 4\9) : (1\3 - 1\4)=
(9/9-4/9):(4/12-3/12)=
5/9:1/12=5/9*12/1=20/3=6 2/3

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=1/2

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

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

2)(1-4/9)÷(1/3-1/4)=(9/9-4/9)÷(4/12-3/12)=
5/9÷1/12=5/9×12/1=20/3=6 2/3;

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=1/2;

4)(5/7-2/3)÷(4/9-5/12)=(15/21-14/21)÷(16/36-15/36)=
1/21÷1/36=1/21×36/1=12/7=1 5/7.