(I think you need a-e, if not let me know and I will edit accordingly)
a: Divide both sides by 4
cm -> 12:8
3:2
b: Convert and divide both sides by 3
cm -> 150:9
50:3
c: Convert and divide both sides by 20
cm -> 100:80
5:4
d: Convert and divide both sides by 4
months -> 4:12
1:3
e: Convert and divide both sides by 250
g -> 2000:250
8:1
Hope this helps, have a nice day :)
