Answer:
10.
Step-by-step explanation:
There are many ways to solve this;
1. the easiest would be to recognize 14:7 is equivalent to 2:1. Which means the left should be twice as large as the right. Twice of 5 is 10.
2. Cross-multiplication/means-extremes theorem can be used: 14/7=x/5 -> 7x=14*5 -> 7x=70 -> x=10
etc.
