Question

Which of the following is the reciprocal of x2 – 2x – 8?

A. (x + 2)(x – 4)

B. 1
(x + 2)(x – 4)

C. 1
(x – 8)

D. 1
(x + 2)

Answer 1

Factor it first.

\(\Large \color{MidnightBlue}{\Rightarrow x^2 -2x -8 = (x + 2)(x - 4) }\)

Now, flip it.

\(\Large \color{MidnightBlue}{\Rightarrow {1 \over (x + 2)(x - 4)} }\)