Question

prove that 3+2 underfoot 5 is irrational

Answer 1

This much answer is enough for 2 marks but if it is asked for 3 or 4 marks then u have to prove that root 5 is irrational

Answer 2

let the given number be rational ,if we add or subtract a rational number in rational number then the resulting number will also be a rational number
then

3+2√5-3
=2√5
again
we divide 2√5 by 5 (same mentioned as above)
2√5/5=√5

and we know that √5 is irrational so the given number is irrational
proved