Решите. 1) (2/7 +5/21): 1 4/7 2) (8/11+3/22): 5/11 3) 1 7/12: (3/8+5/12) 4) 17/36: (7/12-5/9) 5) (3/14+5/7): 3 5/7 6) 19/24: (3/16+5/24)

1) (2/7 +5/21):1 4/7=
( (2•3)/(7•3)+ 5/21) : (1•7+4)/7=
(6/21+ 5/21): 11/7=
11/21• 7/11=
Сокращаем 11 и 11 на 11; 21 и 7 на 7;
1/3• 1/1= 1/3.

2) (8/11+3/22):5/11=
( (8•2)/(11•2) + 3/22))• 11/5=
(16/22+ 3/22)• 11/5=
19/22• 11/5=
Сокращаем 22 и 11 на 11
19/2• 1/5= 19/10= 1 9/10= 1,9.

3) 1 7/12:(3/8+5/12)=
(1•12+7)/12 : ( (3•3)/(8•3)+ (5•2)/(12•2)=
19/12: (9/24+ 10/24)= 19/12: 19/24=
19/12• 24/19=
Сокращаем 19 и 19 на 19; 12 и 24 на 24;
1/1• 2/1= 2.

4) 17/36:(7/12-5/9)=
17/36: ( (7•3)/(12•3) - (5•4)/(9•4))=
17/36: (21/36- 20/36)=
17/36: 1/36= 17/36• 36/1=
Сокращаем 36 и 36 на 36
17/1• 1/1= 17.

5) (3/14+5/7):3 5/7=
(3/14+ (5•2)/(7•2)) : (3•7+5)/7=
(3/14+ 10/14): 26/7=
13/14• 7/26=
Сокращаем 13 и 26 на 13; 14 и 7 на 7;
1/2• 1/2= 1/4.

6) 19/24:(3/16+5/24)=
19/24:( (3•3)/(16•3) + (5•2)/(24•2))=
19/24: (9/48+ 10/48)=
19/24: 19/48=
19/24• 48/19=
Сокращаем 19 и 19 на 19; 24 и 48 на 24;
1/1• 2/1= 2.