Question

simply the following please​

Answer 1

solution:

(√5-√2) (√5+√2) = 3

Answer 2

using (a+b)(a-b)=a²-b²

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