1. m: 12 = 12: 9
m/12 = 12/9
9m = 144
9m/9 = 144/9
m = 16
2. 6: 3 = x: 5
6/3 = x/5
30 = 3x
30/3 = 3x/3
x = 10
3. 10: 8 = 5: y
10/8 = 5/y
10y = 40
10y/10 = 40/10
y = 4
4. 8: p = 4: 3
8/p = 4/3
24 = 4p
24/4 = 4p/4
p = 6
5. 15: 6 = 10: s
15/6 = 10/s
15s = 60
15s/15 = 60/15
s = 4
:)