Question -
Answer -
Let 2 – 3 √5 is not an irrational number and let 2 – 3 √5 is a rational number
Let 2 – 3 √5 = a/b where a and b are positive prime integers
⟹2b−a3b=√5
√5 is a rational
But √5 is an irrational number
Our supposition is wrong
2 – 3 √5 is an irrational