Find
$$\lim _ { x \rightarrow 7 } \frac { x - 8 } { x ^ { 2 } + 12 x + 27 }$$
by direct substitution.
A) $\frac { 1 } { 160 }$
B) $- \frac { 1 } { 160 }$
C) 0
D) $\infty$
E) limit does not exist

Question

Quizplus · Accepted Answer

By direct substitution, we get
$$\lim _ { x \rightarrow 7 } \frac { x - 8 } { x ^ { 2 } + 12 x + 27 } = \frac{7-8}{7^2+12\cdot 7 + 27} = -\frac{1}{160}$$
Therefore, the answer is choice B.

Find lim⁡x→7x−8x2+12x+27\lim _ { x \rightarrow 7 } \frac { x - 8 } { x ^ { 2 } + 12 x + 27 }x→7lim​x2+12x+27x−8​

Find $\lim _ { x \rightarrow 7 } \frac { x - 8 } { x ^ { 2 } + 12 x + 27 }$