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Find 
lim_(x rarr-4)(x^(2)-16)/(x^(2)+4x).
Choose 1 answer:
(A) 2
(B) -2
(c) 0
(D) The limit doesn't exist

Find limx4x216x2+4x \lim _{x \rightarrow-4} \frac{x^{2}-16}{x^{2}+4 x} .\newlineChoose 11 answer:\newline(A) 22\newline(B) 2-2\newline(C) 00\newline(D) The limit doesn't exist

Full solution

Q. Find limx4x216x2+4x \lim _{x \rightarrow-4} \frac{x^{2}-16}{x^{2}+4 x} .\newlineChoose 11 answer:\newline(A) 22\newline(B) 2-2\newline(C) 00\newline(D) The limit doesn't exist
  1. Substitute and Check: First, let's try to directly substitute the value of xx with 4-4 into the function to see if it results in an indeterminate form.\newlineSubstitute 4-4 for xx in (x216)/(x2+4x)(x^2 - 16)/(x^2 + 4x).\newlinelimx4(x216)/(x2+4x)\lim_{x \to -4}(x^2 - 16)/(x^2 + 4x)\newline= ((\-4)^2 - 16)/((\-4)^2 + 4(\-4))\newline= (1616)/(1616)(16 - 16)/(16 - 16)\newline= 0/00/0\newlineWe get an indeterminate form of 0/00/0, which means we need to simplify the expression further to find the limit.
  2. Factor Numerator and Denominator: Since we have an indeterminate form, we can try to factor the numerator and the denominator to see if any common factors can be canceled out.\newlineFactor the numerator (x216)(x^2 - 16) and the denominator (x2+4x)(x^2 + 4x).\newlineThe numerator is a difference of squares and can be factored as (x+4)(x4)(x + 4)(x - 4).\newlineThe denominator can be factored by taking xx common, resulting in x(x+4)x(x + 4).\newlineSo the expression becomes:\newlinelimx4(x+4)(x4)x(x+4)\lim_{x \rightarrow -4}\frac{(x + 4)(x - 4)}{x(x + 4)}
  3. Cancel Common Factor: Now, we can cancel out the common factor (x+4)(x + 4) from the numerator and the denominator.\newlinelimx4(x+4)(x4)x(x+4)=limx4x4x\lim_{x \to -4}\frac{(x + 4)(x - 4)}{x(x + 4)} = \lim_{x \to -4}\frac{x - 4}{x}\newlineNow that the expression is simplified, we can substitute 4-4 for xx again to find the limit.
  4. Substitute and Simplify: Substitute 4-4 for xx in the simplified expression (x4)/x(x - 4)/x.\newlinelimx4x4x\lim_{x \to -4}\frac{x - 4}{x}\newline= \frac{4-4 - 44}{4-4}\newline= \frac{8-8}{4-4}\newline= 22\newlineThe limit exists and is equal to 22.

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