Hello Veritas,
I am going over my notes. I did not right down the correct solution for question 97 in the essentials course prep supplement. I couldn't find it in the books either so if it is explained in books or On-demand please point me in that direction.

In section 7.3:

( sqrt(8+sqrt63 + sqrt(8-sqrt63 )^2

having a really tough time answer key says ans is C. 18

Thanks again,
John

a = sqrt(8 + sqrt(63))

b = sqrt(8 - sqrt(63))

(a + b)^2 = a^2 + 2ab + b^2

= (8 + sqrt(63)) + 2 * sqrt(8 + sqrt(63)) * sqrt(8 - sqrt(63)) + (8 - sqrt(63))

= 8 + sqrt(63) + 2 * sqrt(8 + sqrt(63)) * sqrt(8 - sqrt(63)) + 8 - sqrt(63)

= 16 + 2 * sqrt ( (8 + sqrt(63)) * (8 - sqrt(63) )

= 16 + 2 * sqrt( 64 - 63)

= 18


- Veritas Help

Thanks now I can finally go to sleep. Epic fail on that problem its been driving me nuts I knew you had to foil it but I was doing it wrong.