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Questions: Algebra BusinessCalculus
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Find the limit, if it exists \(\displaystyle \lim_{x \to 4 }\frac{ \frac{5}{x} - \frac{5}{4} }{ x - 4 }\)
Building the fraction by multiplying by the LCD in the numerator and denominator gives: \begin{equation*} \frac{ \frac{5}{x} - \frac{5}{4} }{ x - 4 }\left(\frac{ 4 x }{ 4 x } \right)=\frac{ 20 - 5 x }{ 4 x \left(x - 4\right) } = \frac{ - 5 \left(x - 4\right) }{ 4 x \left(x - 4\right) } = - \frac{5}{4 x}\end{equation*}The reduced function is continuous at \(\displaystyle x = 4\) and by the evaluation theorem \(\displaystyle \lim_{x \to 4 }- \frac{5}{4 x} = - \frac{5}{16}\)
\begin{question}Find the limit, if it exists $\lim_{x \to 4 }\frac{ \frac{5}{x} - \frac{5}{4} }{ x - 4 }$ \soln{9cm}{Building the fraction by multiplying by the LCD in the numerator and denominator gives: \begin{equation*} \frac{ \frac{5}{x} - \frac{5}{4} }{ x - 4 }\left(\frac{ 4 x }{ 4 x } \right)=\frac{ 20 - 5 x }{ 4 x \left(x - 4\right) } = \frac{ - 5 \left(x - 4\right) }{ 4 x \left(x - 4\right) } = - \frac{5}{4 x}\end{equation*}The reduced function is continuous at $x = 4$ and by the evaluation theorem $\lim_{x \to 4 }- \frac{5}{4 x} = - \frac{5}{16}$} \end{question}
\documentclass{article} \usepackage{tikz} \usepackage{amsmath} \usepackage[margin=2cm]{geometry} \usepackage{tcolorbox} \newcounter{ExamNumber} \newcounter{questioncount} \stepcounter{questioncount} \newenvironment{question}{{\noindent\bfseries Question \arabic{questioncount}.}}{\stepcounter{questioncount}} \renewcommand{\labelenumi}{{\bfseries (\alph{enumi})}} \newif\ifShowSolution \newcommand{\soln}[2]{% \ifShowSolution% \noindent\begin{tcolorbox}[colframe=blue,title=Solution]#2\end{tcolorbox}\else% \vspace{#1}% \fi% }% \newcommand{\hideifShowSolution}[1]{% \ifShowSolution% % \else% #1% \fi% }% \everymath{\displaystyle} \ShowSolutiontrue \begin{document}\begin{question}(10pts) The question goes here! \soln{9cm}{The solution goes here.} \end{question}\end{document}
<p> <p>Find the limit, if it exists <img class="equation_image" title=" \displaystyle \lim_{x \to 4 }\frac{ \frac{5}{x} - \frac{5}{4} }{ x - 4 } " src="/equation_images/%20%5Cdisplaystyle%20%5Clim_%7Bx%20%5Cto%204%20%7D%5Cfrac%7B%20%5Cfrac%7B5%7D%7Bx%7D%20-%20%5Cfrac%7B5%7D%7B4%7D%20%7D%7B%20x%20-%204%20%7D%20" alt="LaTeX: \displaystyle \lim_{x \to 4 }\frac{ \frac{5}{x} - \frac{5}{4} }{ x - 4 } " data-equation-content=" \displaystyle \lim_{x \to 4 }\frac{ \frac{5}{x} - \frac{5}{4} }{ x - 4 } " /> </p> </p>
<p> <p>Building the fraction by multiplying by the LCD in the numerator and denominator gives: <img class="equation_image" title=" \frac{ \frac{5}{x} - \frac{5}{4} }{ x - 4 }\left(\frac{ 4 x }{ 4 x } \right)=\frac{ 20 - 5 x }{ 4 x \left(x - 4\right) } = \frac{ - 5 \left(x - 4\right) }{ 4 x \left(x - 4\right) } = - \frac{5}{4 x} " src="/equation_images/%20%20%5Cfrac%7B%20%5Cfrac%7B5%7D%7Bx%7D%20-%20%5Cfrac%7B5%7D%7B4%7D%20%7D%7B%20x%20-%204%20%7D%5Cleft%28%5Cfrac%7B%204%20x%20%7D%7B%204%20x%20%7D%20%5Cright%29%3D%5Cfrac%7B%2020%20-%205%20x%20%7D%7B%204%20x%20%5Cleft%28x%20-%204%5Cright%29%20%7D%20%3D%20%5Cfrac%7B%20-%205%20%5Cleft%28x%20-%204%5Cright%29%20%7D%7B%204%20x%20%5Cleft%28x%20-%204%5Cright%29%20%7D%20%3D%20-%20%5Cfrac%7B5%7D%7B4%20x%7D%20" alt="LaTeX: \frac{ \frac{5}{x} - \frac{5}{4} }{ x - 4 }\left(\frac{ 4 x }{ 4 x } \right)=\frac{ 20 - 5 x }{ 4 x \left(x - 4\right) } = \frac{ - 5 \left(x - 4\right) }{ 4 x \left(x - 4\right) } = - \frac{5}{4 x} " data-equation-content=" \frac{ \frac{5}{x} - \frac{5}{4} }{ x - 4 }\left(\frac{ 4 x }{ 4 x } \right)=\frac{ 20 - 5 x }{ 4 x \left(x - 4\right) } = \frac{ - 5 \left(x - 4\right) }{ 4 x \left(x - 4\right) } = - \frac{5}{4 x} " /> The reduced function is continuous at <img class="equation_image" title=" \displaystyle x = 4 " src="/equation_images/%20%5Cdisplaystyle%20x%20%3D%204%20" alt="LaTeX: \displaystyle x = 4 " data-equation-content=" \displaystyle x = 4 " /> and by the evaluation theorem <img class="equation_image" title=" \displaystyle \lim_{x \to 4 }- \frac{5}{4 x} = - \frac{5}{16} " src="/equation_images/%20%5Cdisplaystyle%20%5Clim_%7Bx%20%5Cto%204%20%7D-%20%5Cfrac%7B5%7D%7B4%20x%7D%20%3D%20-%20%5Cfrac%7B5%7D%7B16%7D%20" alt="LaTeX: \displaystyle \lim_{x \to 4 }- \frac{5}{4 x} = - \frac{5}{16} " data-equation-content=" \displaystyle \lim_{x \to 4 }- \frac{5}{4 x} = - \frac{5}{16} " /> </p> </p>