Simplify the following:
(sqrt(5) + 1) (sqrt(5) - 1) + 5 sqrt(5)
(sqrt(5) + 1) (sqrt(5) - 1) = -1 + 1 sqrt(5) - sqrt(5) + sqrt(5) sqrt(5) = -1 + sqrt(5) - sqrt(5) + 5 = 4:
Answer: 4 + 5 sqrt(5) or decimal 15.18033988749894848204586834365638117720309179805762862135
