I need to identify the value of x that makes each pair of ratios equivalent
1. 2:x and 12:18
2. 5:15 and x:3
3. x:4 and 45:20
4. 21 to x and 7 to 10
5. x to 50 and 16 to 25
6. 6 to 8 and 18 to x
7. 9/36 and x/4
8. 42/22 and 21/x
9. x/7 and 5/1
10. 20/x 4/8
i cant even understand the subject its too hard for me