Question

Which of the following is a rational number?
square root 15 square root 16, square root 21, square root 22

Answer 1

Can someone please help!!!!!!!!!!!1

Answer 2

thoughts?

remember that, for square roots:

- the square root of a perfect square (like 1, 4, 9,e tc.) will be rational
- the square root of a non-perfect square (like 2, 5, 7, etc.) will be irrational.

so out of 15, 16, 21, or 22 which one is a perfect square? if you're still in doubt, evaluate sqrt(15), sqrt(16), sqrt(21) and sqrt(22) to see which one gives you an integer result