Question

simplyfy: (5+√5)(5-√5)​

Answer 1

$(5 + \sqrt{5})(5 - \sqrt{5} ) \\ {(5)}^{2} - {( \sqrt{5} )}^{2} \\ 25 - 5 = 20$

Hence,

${\boxed{\red{\large{(5 + \sqrt{5})(5 - \sqrt{5} ) = 20}}}}$

Answer 2

Answer:   20

[5+ROOT5][5-ROOT5]= [5]2 -  [ROOT5]2= 25- 5 = 20

THIS IS SOLVED USING a2-b2 formula