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
help plz
They are all the same, I will one #4
21 to x and 7 to 10
21/x = 7/10
cross-multiply
7x = 210
x = 210/7 = 30
notice that if a : b = c : d, then cross-multiplication results in
bc = ad