cara penyelesaian ,makasih

23. 7/13 + 4/13
= 11/13

24. 6/7 + 3/4
= 24/28 + 21/28
= 45/28
= 1 17/28

25. 9/16 - 6/16
= 3/16

26. 7/8 - 3/5
= 35/40 - 24/40
= 11/40

27. 4/13 x 6/7
= 24/91

28. 7/15 : 6/13
= 7/15 x 13/6
= 91/90
= 1 1/90