Por fabor ayudemen com la 23 com el prosedimiento 24 25?

23. a.

- 5 / 7 + 3 / 7 = ( - 35 + 27) / 63 = - 8 / 63

b.

8 / 25 + 12 / 45 = 8 / 25 + 4 / 15 = (120 + 100) / 375 = 220 / 375 = 44 / 75

c.

4 / 24 + 5 / 32 = 1 / 6 + 5 / 32 = (32 + 30) / 192 = 62 / 192 = 31 / 96

d.

- 15 / 9 + 1 / 24 = - 5 / 3 + 1 / 24 = ( - 120 + 3) / 72 = - 117 / 72 = - 13 / 8

e.

9 / 18 + 2 / 14 = 1 / 2 + 1 / 7 = (7 + 2) / 14 = 9 / 14

f.

- 4 / 12 + 6 / 30 = - 1 / 3 + 1 / 5 = ( - 5 + 3) / 15 = - 2 / 15

g.

- 5 / 12 + ( - 2 / 15) = - 5 / 12 - 2 / 15 = ( - 75 - 24) / 180 = - 99 / 180 = - 11 / 20

h.

- 4 / 9 + ( - 11 / 7) = - 28 - 99 / 63 = - 127 / 63

i.

4 / 17 + ( - 6 / 46) = 4 / 17 - 6 / 46 = 4 / 17 - 3 / 23 = (92 - 51) / 391 = 41 / 391

j.

10 / 12 + 4 / 15 = 5 / 6 + 4 / 15 = (75 + 24) / 90 = 99 / 90 = 11 / 10

24.

A. 8 / 9 - 3 / 10 = (80 - 27) / 90 = 53 / 90

b.

- 3 / 5 - 1 / 3 = - 9 - 5 / 15 = - 14 / 15

c.

8 / 15 - ( - 5 / 12) = 8 / 15 + 5 / 12 = (96 + 75) / 180 = 171 / 180 = 19 / 20

d.

( - 4 / 9) - ( - 5 / 18) = - 4 / 9 + 5 / 18 = ( - 72 + 45) / 162 = - 27 / 162 = - 3 / 18

e.

3 / 4 - ( - 7 / 3) = 3 / 4 + 7 / 3 = (9 + 28) / 12 = 37 / 12

f.

7 / 2 - ( - 9 / 4) = 7 / 2 + 9 / 4 = (28 + 18) / 8 = 46 / 8 = 23 / 4

25.

A. ( - 3 / 7)÷4 / 12 = - 9 / 7

b.

41 / 3÷22 / 5 = 205 / 66

c.

15 / 11÷4 / 5 = 75 / 44

d.

17 / 5÷4 / 3 = 51 / 20

e.

1 / 2÷1 / 3 = 3 / 2

f.

( - 19 / 8)×( - 12 / 7) = 57 / 14

g.

(12 / 5×7 / 4)÷3 / 2 = 21 / 5÷3 / 2 = 42 / 15 = 14 / 5

h.

(9 / 8×5 / 4)÷(1 / 4×11 / 3) = 45 / 32÷11 / 12 = 540 / 352 = 270 / 176 = 135 / 88.