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Find \lim\limits_{x \to 3} \frac{2x^{2} + x - 21}{x - 3}.

A.

0

B.

1

C.

7

D.

13

Correct answer is D

\lim\limits_{x \to 3} \frac{2x^{2} + x - 21}{x - 3}

2x^{2} + x - 21 = 2x^{2} - 6x + 7x - 21 (by factorizing)

= (2x + 7)(x - 3)

\therefore \lim\limits_{x \to 3} \frac{2x^{2} + x - 21}{x - 3} \equiv \lim\limits_{x \to 3} \frac{(2x+7)(x-3)}{x-3}

\lim\limits_{x \to 3} (2x + 7)  = 2(3) + 7 = 13