- A8
- B2√15
- C4
- D8 − 2√15
Step-by-Step Solution
(4 − √15)(4 + √15) = 16 − 15 = 1, so 1/a = 4 + √15. Then a + 1/a = (4 − √15) + (4 + √15) = 8.
Answer: A) 8
Given a = 4 − √15, find the value of a + 1/a.
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