Question

simplify (5+√5) (5-√5)​

Answer 1

or another way is you can use the identity a^2-b^2

Answer 2

★$\large\color{red} \mathrm{Hey \: There!}$★

It is true that: (a^2-b^2) = (a+b)(a-b).

Thus,

(5+√5)(5-√5)

= (5)^2 - (√5)^2

= 25 - 5

= 20