Question

Which number is irrational and why?


`\sqrt{ (4 )/(9) }`

`√(20)`

`√(121)`

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Answer 1

The answer is the second choice: √20

Step-by-step explanation:

It is irrational. It simplifies to 2√5, but this is also irrational. To be rational, the decimal would have to be able to be written as a fraction. This radical, both 20 and 5, is a non-terminating and non-repeating decimal, so it cannot be written as a fraction.