2012 · Q49
If x + 1/x = a, then what is x^3 + x^2 + 1/x^3 + 1/x^2 equal to?
Elementary MathematicsAlgebra
- Aa^3 + a^2
- Ba^3 + a^2 - 5a
- Ca^3 + a^2 - 3a - 2
- Da^3 + a^2 - 4a - 2
Explanation
x^3+1/x^3 = a^3-3a and x^2+1/x^2 = a^2-2, whose sum is a^3+a^2-3a-2.