Question

Which two numbers are irrational? How do you know?
a. 8-√56
b. 8-√25
c. 2-√73

Answer 1

A and C are irrational.

We know that B is rational because it's just asking 8 - 5, which is 3.

There is, however, no perfect square root of 73 or 56, and so the answer will be irrational.

Answer 2

A and C are irrational because they are non-termininating decimals.

If you have any further questions feel free to ask.

Hope this helps.