Question

Show 3 under root 5 is irrational
$3 \sqrt{5}$
please answer fast and correct ​

Answer 1

Answer:

Let √2-3√5 is a rational number

A rational number can be written in the form of p/q where p,q are integers.

√2-3√5=p/q

Squaring on both sides,

(√2-3√5)²=(p/q)²

[√2²+(3√5)²-2(√2)(3√5)]=p²/q²

[2+9(5)-6√10]=p²/q²

[2+45-6√10]=p²/q²

6√10=p²/q²-47

6√10=(p²-47q²)/q²

√10=(p²-47q²)6q²

p,q are integers then (p²-47q²)/6q² is a rational number.

Then,√10 is also a rational number.

But this contradicts the fact that √10 is a rational number.

So,our supposition is false.

Hence,√2-3√5 is irrational number.

Hope it helps

Step-by-step explanation: