Answer:
Square root of 30 is irrational because the answer is a non-terminating decimal.
4/7 is rational because it is a fraction.
21 divided by the square root of 4 is irrational because the result is a non-terminating decimal.
Pi is irrational because it's a non-terminating decimal.
-27 is rational because rational numbers can be positive or negative.
I hope this is correct! :-)
