Question

2-√5 multiplied by 2+√5​

Answer 1

Answer: -1

Step-by-step explanation:

(2-√5)(2+√5​)

= 2^2 - (√5)^2

= 4 - 5

= -1

hope this helped you :)

Answer 2

Answer:

-1

Step-by-step explanation:

we know that

$(a + b) \times (a - b) = {a}^{2} - {b}^{2}$

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

$(2 - \sqrt{5} ) \times (2 + \sqrt{5} ) = - 1$