# Show that the Following Numbers Are Irrational. 7 √ 5 - Mathematics

Numerical

Show that the following numbers are irrational.

$7\sqrt{5}$

#### Solution

Let us assume that 1/sqrt2 is rational .Then , there exist positive co primes a and b such that

7/sqrt5=a/b

sqrt5=a/(7b)

We know that sqrt5 is an irrational number

Here we see that sqrt5 is a rational number which is a contradiction

Hence 7sqrt5 is irrational

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#### APPEARS IN

RD Sharma Class 10 Maths
Chapter 1 Real Numbers
Exercise 1.5 | Q 1.2 | Page 49