Question

2+ root 21 rational or irrational
$2 + \sqrt{21}$
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Answer 1

Answer:

√21 is irrational. Let's assume that √21 is rational. So √21 can be expressed in the form p/q form. p/q is the reduced form of rational number so p and q have no common factors other than 1, i.e. they are co-prime numbers.