Question

Write the value of (3 + √5 ) (3 - √5 ).​

Answer 1

Identity III:

$(x + y)(x - y) = {x}^{2} - {y}^{2}$

Solution:

$(3 + \sqrt{5} )(3 - \sqrt{5} ) = {(3)}^{2} - {( \sqrt{5} )}^{2}$

$= 9 - 5$

$= 4$

Answer 2

Answer:

The correct answer is 4.