Question

Prove that 3 + 2√5 is irrational.​

Answer 1

Prove 3+25 is irrational.

→ let take that 3+25is rational number

→ so, we can write this answer as

⇒3+25=ba 

Here a & b use two coprime number and b=0.

⇒25=ba−3

⇒25=ba−3b

∴5=2ba−3b

Here a and b are integer so 2ba−3b is a rational number so 5 should be rational number but

5 is a irrational number so it is contradict