6/30 = 7/x
5/10 = 3/x
x/15 =4/20
2/x = 10/35
10/12 = x/24
x/12 = 3/18
x/40 = 9/24
4/5 = 8/x
10/x = 5/6
x/6 = 8/12
3/21= 20/x
15
6
4
10
12
20
2
35
3
140
7
