(√17 + 2)^2 − 4 √17
= (17 + 4√17 + 4) - 4√17= 17 + 4√17 + 4 - 4√17= 21
Therefore, (√17 + 2)^2 − 4 √17 = 21.
(√17 + 2)^2 − 4 √17
= (17 + 4√17 + 4) - 4√17
= 17 + 4√17 + 4 - 4√17
= 21
Therefore, (√17 + 2)^2 − 4 √17 = 21.