tolong bantu jawab makasih

1. 40-12=28
28/40x100
70%
2. 8 1/6 = 8,16
7 2/4 =7,5
8,16 + 7,5 = 15,66
15,66 x 2 = 31,32
3. 120 : 40 = 3
80 : 40 = 2
jadi perbandingannya adalah 3:2
4. 5 12/24 - 3 11/12 + 11/18 =
132/24 - 47/12 + 11/18 =
396/72 - 282/72 = 114/72
114/72 + 44/72 = 158/72 = 2 14/72
5. 50/6 x 36/10 = 180/60 : 12/15 =
180/60 x 15/12 = 3 3/4
6. (12-5) 4/8 - 3/6 = 7 cm
7. 12 2/4 = 12,5 x 10 = 125 kg