Ответ:

Пошаговое объяснение:

5.

1) 1. 3/4 + 2. 4/5 =

1. 15/20 + 2. 16/20 =

3. 31/20 = 4. 11/20

2) 4. 11/20 * 30 =

91/20 * 30 = 91/2 * 3 =

273/2 = 136. 1/2

6.

1) 1/13 - 2. 3/4 =

4/52 - 2. 39/52 = -2. 35/52

2) -2. 35/52 * 26 =

-139/52 * 26 = -139/2 * 1 = -139/2 = -69. 1/2

7.

1) 12/17 + 2. 7/11 =

132/187 + 2. 119/187 =

2. 251/187 = 3. 64/187

2) 1. 8/17 : 3. 64/187 =

25/17 : 625/187 =

25/17 * 187/625 =

1/1 * 11/25 = 11/25

8.

1) 1. 5/9 - 4/7 =

1. 35/63 - 36/63 =

98/63 - 36/63 = 62/63

2) 3. 4/9 : 62/63 =

31/9 : 62/63 = 31/9 * 63/62 = 1/1 * 7/2 = 7/2 = 3. 1/2

Ответ:

5.  136 1/2

6. -69 1/2

7. 11/25

8. 3 1/2

Пошаговое объяснение:

5. (1 3/4+2 4/5)*30 = (7/4+14/5)*30 = (35/20+56/20)*30 =

91/20*30 = 273/2 = 136 1/2

6. (1/13-2 3/4)*26 = (1/13-11/4)*26 = (4/52-143/52)*26 = -139/52*26 = -69 1/2

7. 1 8/17:(12/17+2 7/11) = 25/17:(12/17+29/11) = 25/17:(132/187+493/187) =

25/17:625/187 = 25/17*187/625 = 11/25

8. 3 4/9:(1 5/9-4/7) = 31/9:(14/9-4/7) = 31/9:(98/63-36/63)=

31/9:62/63 = 31/9*63/62 = 7/2 = 3 1/2