tolong bantu aku dong nomor: 3, 4, 5, 6, 8, 9

3.) 1/4 + 3/8 + 2/5 =
= 10/40 + 15/40 + 16/40
= 41/40
= 1 1/40
4.) 8 3/4 - 4 4/8 - 2 2/5
= (8 6/8 - 4 4/8) - 2 2/5
= 4 2/8 - 2 2/5
= 4 1/4 - 2 2/5
= 4 5/20 - 2 8/20
= 3 25/20 - 2 8/20
= 1 17/20
5.) 2 5/6 + 1 2/5 - 4/15
= (2 25/30 + 1 12/30) - 4/15
= 3 37/30 - 4/15
= 3 37/30 - 8/30
= 3 29/30
6.) 42,75 - 15,8 - 16,24
= (42,75 - 15,8) - 16,24
= 26,95 - 16,24
= 10,71
8.) 3 2/3 + 3/5
= 3 10/15 + 9/15
= 3 19/15
= 4 4/15
9.) 4 3/4 + 2 1/3 - 5/6
= (4 9/12 + 2 4/12) - 5/6
= 6 13/12 - 10/12
= 6 3/12
= 6 1/4

semoga membantu :)