Question

Simplify (4 + sqrt(5))(4 - sqrt(5)) and identify whether the number is rational irrational​

Answer 1

Answer:

(4+√5)(4-√5)

(4)^2 - (√5)^2 (a^2-b^2) = (a+b)(a-b)

16 - 5

11

Therefore the number is rational.

Answer 2

Step-by-step explanation:

(4+√5)(4-√5)

(4)^2 - (√5)^2 (a^2-b^2) = (a+b)(a-b)

16-5

11

Therefore the number is rational.