Answer:
The missing numerator is 15.
Step-by-step explanation:
It's 15 because 5/7 and 15/21 are equivalent fractions.
First think about what number multiplied by seven can give you 21. 3 multiplied by seven can give you 21. Also, remember that what you multiply on the bottom, you have to do the same to the top. So 5 multiplied by 3 will give you 15, the answer.
