HELP ME!!! (4+√2)^2 - 4√8 = ?1 - (2√7+8) × (2√7 -8) = ?

Question

HELP ME!!!
(4+√2)^2 - 4√8 = ?
1 - (2√7+8) × (2√7 -8) = ?

Answer 1

(4+√2)^2 - 4√8 = 16 + 2*4*√2 + 2 - 4√8 = 16 + 8√2 + 2 - 4√8 =
18 + 8√2 - 4√8 = 18 + 8√2 - 4√4*2 = 18 + 8√2 - 8√2 = 18.

1 - (2√7+8)*(2√7 -8) = 1 - (2√7)² - 64 = - 63 - (√4*7)² = - 63 - (√28)² =
- 63 - 28 = - 91.