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Multiple Choice
Find the limit. limx→−2x+2x2−5x−14
A
−9
B
−2
C
0
D
Does not exist
Verified step by step guidance
1
Step 1: Recognize that the given problem involves finding the limit of a rational function as x approaches -2. The function is \( \frac{x^2 - 5x - 14}{x + 2} \). Start by checking if direct substitution of \( x = -2 \) into the function results in an indeterminate form (e.g., \( \frac{0}{0} \)).
Step 2: Substitute \( x = -2 \) into the numerator \( x^2 - 5x - 14 \) and denominator \( x + 2 \). For the numerator, calculate \( (-2)^2 - 5(-2) - 14 \). For the denominator, calculate \( -2 + 2 \). If both numerator and denominator equal zero, the expression is indeterminate, and further simplification is needed.
Step 3: Factorize the numerator \( x^2 - 5x - 14 \). Look for two numbers that multiply to \( -14 \) and add to \( -5 \). The factorization is \( (x - 7)(x + 2) \). Rewrite the function as \( \frac{(x - 7)(x + 2)}{x + 2} \).
Step 4: Simplify the expression by canceling the common factor \( x + 2 \) in the numerator and denominator. This is valid as long as \( x \neq -2 \), since division by zero is undefined. The simplified function is \( x - 7 \).
Step 5: Evaluate the limit of the simplified function \( x - 7 \) as \( x \to -2 \). Substitute \( x = -2 \) into \( x - 7 \) to find the limit. The result is the value of the limit.