Question

prove that 3 minus root 5 is an irrational if 3 is arational and root 5 is irrational ​

Answer 1

root 5 is irrational number
let us assume that root 5 is rational number
and rational number is denoted by p/q
root 5 =p/q
root5q =p
on left hand side root5 is irrational number
on right hand side p is rational number
our assumption is wrong
hence
root 5 is irrational number