2022 · Q26
If a + b = 2, (1)/(a) + (1)/(b) = 2 then what is the value of a³ + b³?
Elementary MathematicsAlgebra
- A2
- B4
- C6
- D8
Explanation
From 1/a+1/b = (a+b)/ab = 2 and a+b = 2 we get ab = 1. Then a³+b³ = (a+b)³-3ab(a+b) = 8-6 = 2. Hence the keyed option is A.