<item ident="E3-0007" title="E3 | Solving linear systems | ver. 0007"> <itemmetadata> <qtimetadata> <qtimetadatafield> <fieldlabel>question_type</fieldlabel> <fieldentry>essay_question</fieldentry> </qtimetadatafield> </qtimetadata> </itemmetadata> <presentation> <material> <mattextxml> <div class="exercise-statement"> <p> <strong>E3.</strong> </p> <p>Show how to find the solution set for the following system of linear equations. <p style="text-align:center;"><img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?\begin{matrix} -2 \, x_{1} & + & x_{2} & - & 4 \, x_{3} & = & 3 \\ -3 \, x_{1} & - & 2 \, x_{2} & - & 7 \, x_{3} & = & -3 \\ & & x_{2} & & & = & 4 \\ x_{1} & & & + & 2 \, x_{3} & = & 0 \\ \end{matrix}" alt="\begin{matrix} -2 \, x_{1} & + & x_{2} & - & 4 \, x_{3} & = & 3 \\ -3 \, x_{1} & - & 2 \, x_{2} & - & 7 \, x_{3} & = & -3 \\ & & x_{2} & & & = & 4 \\ x_{1} & & & + & 2 \, x_{3} & = & 0 \\ \end{matrix}" title="\begin{matrix} -2 \, x_{1} & + & x_{2} & - & 4 \, x_{3} & = & 3 \\ -3 \, x_{1} & - & 2 \, x_{2} & - & 7 \, x_{3} & = & -3 \\ & & x_{2} & & & = & 4 \\ x_{1} & & & + & 2 \, x_{3} & = & 0 \\ \end{matrix}" data-latex="\begin{matrix} -2 \, x_{1} & + & x_{2} & - & 4 \, x_{3} & = & 3 \\ -3 \, x_{1} & - & 2 \, x_{2} & - & 7 \, x_{3} & = & -3 \\ & & x_{2} & & & = & 4 \\ x_{1} & & & + & 2 \, x_{3} & = & 0 \\ \end{matrix}"/></p></p> </div> </mattextxml> <mattext texttype="text/html"><div class="exercise-statement"> <p> <strong>E3.</strong> </p> <p>Show how to find the solution set for the following system of linear equations. </p> <p style="text-align:center;"><img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?%5Cbegin%7Bmatrix%7D%20-2%20%5C,%20x_%7B1%7D%20&amp;%20+%20&amp;%20x_%7B2%7D%20&amp;%20-%20&amp;%204%20%5C,%20x_%7B3%7D%20&amp;%20=%20&amp;%203%20%5C%5C%20-3%20%5C,%20x_%7B1%7D%20&amp;%20-%20&amp;%202%20%5C,%20x_%7B2%7D%20&amp;%20-%20&amp;%207%20%5C,%20x_%7B3%7D%20&amp;%20=%20&amp;%20-3%20%5C%5C%20&amp;%20&amp;%20x_%7B2%7D%20&amp;%20&amp;%20&amp;%20=%20&amp;%204%20%5C%5C%20x_%7B1%7D%20&amp;%20&amp;%20&amp;%20+%20&amp;%202%20%5C,%20x_%7B3%7D%20&amp;%20=%20&amp;%200%20%5C%5C%20%5Cend%7Bmatrix%7D" alt="\begin{matrix} -2 \, x_{1} &amp; + &amp; x_{2} &amp; - &amp; 4 \, x_{3} &amp; = &amp; 3 \\ -3 \, x_{1} &amp; - &amp; 2 \, x_{2} &amp; - &amp; 7 \, x_{3} &amp; = &amp; -3 \\ &amp; &amp; x_{2} &amp; &amp; &amp; = &amp; 4 \\ x_{1} &amp; &amp; &amp; + &amp; 2 \, x_{3} &amp; = &amp; 0 \\ \end{matrix}" title="\begin{matrix} -2 \, x_{1} &amp; + &amp; x_{2} &amp; - &amp; 4 \, x_{3} &amp; = &amp; 3 \\ -3 \, x_{1} &amp; - &amp; 2 \, x_{2} &amp; - &amp; 7 \, x_{3} &amp; = &amp; -3 \\ &amp; &amp; x_{2} &amp; &amp; &amp; = &amp; 4 \\ x_{1} &amp; &amp; &amp; + &amp; 2 \, x_{3} &amp; = &amp; 0 \\ \end{matrix}" data-latex="\begin{matrix} -2 \, x_{1} &amp; + &amp; x_{2} &amp; - &amp; 4 \, x_{3} &amp; = &amp; 3 \\ -3 \, x_{1} &amp; - &amp; 2 \, x_{2} &amp; - &amp; 7 \, x_{3} &amp; = &amp; -3 \\ &amp; &amp; x_{2} &amp; &amp; &amp; = &amp; 4 \\ x_{1} &amp; &amp; &amp; + &amp; 2 \, x_{3} &amp; = &amp; 0 \\ \end{matrix}"></p> </div> </mattext> </material> <response_str ident="response1" rcardinality="Single"> <render_fib> <response_label ident="answer1" rshuffle="No"/> </render_fib> </response_str> </presentation> <itemfeedback ident="general_fb"> <flow_mat> <material> <mattextxml> <div class="exercise-answer"> <h4>Partial Answer:</h4> <p style="text-align:center;"> <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?\mathrm{RREF} \left[\begin{array}{ccc|c} -2 & 1 & -4 & 3 \\ -3 & -2 & -7 & -3 \\ 0 & 1 & 0 & 4 \\ 1 & 0 & 2 & 0 \end{array}\right] = \left[\begin{array}{ccc|c} 1 & 0 & 0 & 0 \\ 0 & 1 & 0 & 0 \\ 0 & 0 & 1 & 0 \\ 0 & 0 & 0 & 1 \end{array}\right]" alt="\mathrm{RREF} \left[\begin{array}{ccc|c} -2 & 1 & -4 & 3 \\ -3 & -2 & -7 & -3 \\ 0 & 1 & 0 & 4 \\ 1 & 0 & 2 & 0 \end{array}\right] = \left[\begin{array}{ccc|c} 1 & 0 & 0 & 0 \\ 0 & 1 & 0 & 0 \\ 0 & 0 & 1 & 0 \\ 0 & 0 & 0 & 1 \end{array}\right]" title="\mathrm{RREF} \left[\begin{array}{ccc|c} -2 & 1 & -4 & 3 \\ -3 & -2 & -7 & -3 \\ 0 & 1 & 0 & 4 \\ 1 & 0 & 2 & 0 \end{array}\right] = \left[\begin{array}{ccc|c} 1 & 0 & 0 & 0 \\ 0 & 1 & 0 & 0 \\ 0 & 0 & 1 & 0 \\ 0 & 0 & 0 & 1 \end{array}\right]" data-latex="\mathrm{RREF} \left[\begin{array}{ccc|c} -2 & 1 & -4 & 3 \\ -3 & -2 & -7 & -3 \\ 0 & 1 & 0 & 4 \\ 1 & 0 & 2 & 0 \end{array}\right] = \left[\begin{array}{ccc|c} 1 & 0 & 0 & 0 \\ 0 & 1 & 0 & 0 \\ 0 & 0 & 1 & 0 \\ 0 & 0 & 0 & 1 \end{array}\right]"/> </p> <p>The solution set is <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?\left\{\right\}" alt="\left\{\right\}" title="\left\{\right\}" data-latex="\left\{\right\}"/>.</p> </div> </mattextxml> <mattext texttype="text/html"><div class="exercise-answer"> <h4>Partial Answer:</h4> <p style="text-align:center;"> <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?%5Cmathrm%7BRREF%7D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Cc%7D%20-2%20&amp;%201%20&amp;%20-4%20&amp;%203%20%5C%5C%20-3%20&amp;%20-2%20&amp;%20-7%20&amp;%20-3%20%5C%5C%200%20&amp;%201%20&amp;%200%20&amp;%204%20%5C%5C%201%20&amp;%200%20&amp;%202%20&amp;%200%20%5Cend%7Barray%7D%5Cright%5D%20=%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Cc%7D%201%20&amp;%200%20&amp;%200%20&amp;%200%20%5C%5C%200%20&amp;%201%20&amp;%200%20&amp;%200%20%5C%5C%200%20&amp;%200%20&amp;%201%20&amp;%200%20%5C%5C%200%20&amp;%200%20&amp;%200%20&amp;%201%20%5Cend%7Barray%7D%5Cright%5D" alt="\mathrm{RREF} \left[\begin{array}{ccc|c} -2 &amp; 1 &amp; -4 &amp; 3 \\ -3 &amp; -2 &amp; -7 &amp; -3 \\ 0 &amp; 1 &amp; 0 &amp; 4 \\ 1 &amp; 0 &amp; 2 &amp; 0 \end{array}\right] = \left[\begin{array}{ccc|c} 1 &amp; 0 &amp; 0 &amp; 0 \\ 0 &amp; 1 &amp; 0 &amp; 0 \\ 0 &amp; 0 &amp; 1 &amp; 0 \\ 0 &amp; 0 &amp; 0 &amp; 1 \end{array}\right]" title="\mathrm{RREF} \left[\begin{array}{ccc|c} -2 &amp; 1 &amp; -4 &amp; 3 \\ -3 &amp; -2 &amp; -7 &amp; -3 \\ 0 &amp; 1 &amp; 0 &amp; 4 \\ 1 &amp; 0 &amp; 2 &amp; 0 \end{array}\right] = \left[\begin{array}{ccc|c} 1 &amp; 0 &amp; 0 &amp; 0 \\ 0 &amp; 1 &amp; 0 &amp; 0 \\ 0 &amp; 0 &amp; 1 &amp; 0 \\ 0 &amp; 0 &amp; 0 &amp; 1 \end{array}\right]" data-latex="\mathrm{RREF} \left[\begin{array}{ccc|c} -2 &amp; 1 &amp; -4 &amp; 3 \\ -3 &amp; -2 &amp; -7 &amp; -3 \\ 0 &amp; 1 &amp; 0 &amp; 4 \\ 1 &amp; 0 &amp; 2 &amp; 0 \end{array}\right] = \left[\begin{array}{ccc|c} 1 &amp; 0 &amp; 0 &amp; 0 \\ 0 &amp; 1 &amp; 0 &amp; 0 \\ 0 &amp; 0 &amp; 1 &amp; 0 \\ 0 &amp; 0 &amp; 0 &amp; 1 \end{array}\right]"> </p> <p>The solution set is <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?%5Cleft%5C%7B%5Cright%5C%7D" alt="\left\{\right\}" title="\left\{\right\}" data-latex="\left\{\right\}">.</p> </div> </mattext> </material> </flow_mat> </itemfeedback> </item>