Answer:
√37
Explanation:
An irrational number is a number that never terminates nor repeats.
Let's go through each of the answer choices.
1) √100 is just 10. This is not irrational.
2) √81 is just 9. This is again not irrational.
3) √64 is 8. Not irrational.
4) √49 is 7. Again, not irrational.
5) √37 is 6.08276253... This number will never end and it doesn't repeat. Therefore, √37 is irrational.
And this is our answer.
And we're done!