Question

state whether the number (√3+√5) (√3-√5) is rational or irrational justify

Answer 1

Answer:

on  evaluating  (√3+√5) (√3-√5) ,

(√3+√5) (√3-√5) = (a+b)(a-b)

by identity (a+b)(a-b)= a²-b²

(√3+√5) (√3-√5)= (√3)²-(√5)²

= 3-5=(-2)

-2 can be expressed in p/q form so,  (√3+√5) (√3-√5) is rational