MCQ
$(x^2 - 4x - 21) = ?$
- A$(x + 7) (x - 3)$
- ✓$(x - 7) (x + 3)$
- C$(x - 7) (x - 3)$
- DNone of these.
✓
Answer
Correct option: B.
$(x - 7) (x + 3)$
$(x^2 - 4x - 21) = x^2 - 7x + 3x - 21$
$= x(x - 7) + 3(x - 7)$
$= (x - 7) (x + 3)$
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