Express (frac{1}{x + 1}) – (frac{1}{x – 2}) as a single algebraic fraction

A.
(frac{3}{(x + 1)(2 – x)}) 
B.
(frac{3}{(x + 1)(2 – x)}) 
C.
(frac{1}{(x + 1)}) 
D.
(frac{1}{(x + 1)(x – 2)})
Correct Answer: Option A
Explanation
(frac{1}{x + 1}) – (frac{1}{x – 2}) = (frac{x – 2 – x – 1}{(x + 1)(x – 2)})
= (frac{3}{(x + 1)(2 – x)})