Question

show that 4 - 5 root 2 is irrational numbers

Answer 1

let us assume that 4-5√2 is rational
⇒4-5√2=p/q
⇒4-p/q=5√2
⇒4q-p/q=5√2
⇒4q-p/5q=√2
rational=irrational
which is a contradiction
∴our assumption is wrong
4-5√2 is irrational

Answer 2

answer is in the pic..................