Question

Choose the correct answer from the alternatives given.
If $\frac{1}{a}-\frac{1}{b}=\frac{1}{a-b}$, then the value of $a^3+b^3$ is

• A. 0
• B. -1
• C. 1
• D. 2

Answer 1

The correct option is A 0

$\frac{1}{a}-\frac{1}{b}=\frac{1}{ab}$
$\frac{ba}{ab}=\frac{1}{ab}$
(b a) (a b) = ab
$(ab{)}^2$ + ab = 0
$a^2+b^2-ab=0$
$a^3+b^3=(a+b)(a^2+b^2-ab)$
= (a + b) $\times$ 0 = 0