MCQ
The factors of $a^2 - 1 - 2x - x^2$ are:
- A$(a - x + 1)(a - x - 1)$
- B$(a + x - 1)(a - x + 1)$
- C$(a + x +1)(a - x + 1)$
- ✓None of these.
✓
Answer
Correct option: D.
None of these.
$a^2 - 1 - 2x - x^2$
$= a^2 - (1 + 2x + x^2)$
$= a^2 - (1 + x)^2$
$= [a - (1 + x)][a + (1 + x)]$
$= (a - x - 1)(a + x + 1)$
$= a^2 - (1 + 2x + x^2)$
$= a^2 - (1 + x)^2$
$= [a - (1 + x)][a + (1 + x)]$
$= (a - x - 1)(a + x + 1)$
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