Question

how to know weather a no. is rational or irrational for example 5.√3
2π
2√7/7√7 ​

Answer 1

Answer:

5√3 is an irrational,as we know

Rational number×Irrational Number=Irrational Number

And now

2π is also irrational

as it's 2×π

Also π doesn't have a perfect decimal expansion, it's repeating

Hence, it's irrational

and in case of

$\frac{2 \sqrt{7} }{7 \sqrt{7} }$

We could say it's irrational but it's irrational because we can cancel both √7

which is 2/7

and it's rational