Question

give reason to show that 4+√5 is a irrational

Answer 1

here is how we do it legislation the contradictory that 4 + root 5 is rational show it can be written in the form of a baby where A and B are co primes
equation for a y b equals to 4 + root 5 square on both sides you can see root 5 is rational but it is wrong hence your assumption is wrong 4 + root 5 is irrational hence proved

Answer 2

Hope this helps you....