If x + 1/x = 5, find the value of x^3 + 1/x^3.
A110
B115
C125
D140
Explanation
x^3 + 1/x^3 = (x + 1/x)^3 – 3(x + 1/x) = 5^3 – 3(5) = 125 – 15 = 110.
Exam Relevance
- Topic: Algebra
- Subtopic: Identities
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