%html %head %script{:type => "text/x-mathjax-config"} MathJax.Hub.Config({tex2jax: {inlineMath: [['$','$'], ['\\(','\\)']]}}); %script{:type => "text/javascript", :src => "http://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML"} :css .solution { border-top: 1px dotted #222; } %body %h2 Solve for $l$: #solve-for-l-01.solution :escaped $$ \begin{eqnarray} -2lmn + 8m - 3n + 9 & = & -5m + 3n - 7 \\ -2lmn + 8m - 3n + 9 - 9 & = & -5m + 3n - 7 - 9 \\ -2lmn + 8m - 3n & = & -5m + 3n - 16 \\ -2lmn + 8m - 3n + 3n & = & -5m + 3n - 16 + 3n \\ -2lmn + 8m & = & -5m + 3n - 16 + 3n \\ -2lmn + 8m - 8m & = & -5m + 3n - 16 + 3n - 8m \\ -2lmn & = & -5m + 3n - 16 + 3n - 8m \\ \frac{-2lmn}{-2} & = & \frac{-5m + 3n - 16 + 3n - 8m}{-2} \\ lmn & = & \frac{-5m + 3n - 16 + 3n - 8m}{-2} \\ \frac{lmn}{mn} & = & \frac{\frac{-5m + 3n - 16 + 3n - 8m}{-2}}{mn} \\ l & = & \frac{\frac{-5m + 3n - 16 + 3n - 8m}{-2}}{mn} \\ l & = & \frac{\frac{-5m - 16 + 6n - 8m}{-2}}{mn} \\ l & = & \frac{\frac{-16 + 6n - 13m}{-2}}{mn} \\ l & = & \frac{8 - 3n - \frac{13m}{-2}}{mn} \\ \end{eqnarray} $$ #solve-for-l-02.solution :escaped $$ \begin{eqnarray} -2lmn + 8m - 3n + 9 & = & -5m + 3n - 7 \\ -2lmn + 8m - 3n + 9 - 9 & = & -5m + 3n - 7 - 9 \\ -2lmn + 8m - 3n & = & -5m + 3n + 2 \\ -2lmn + 8m - 3n + 3n & = & -5m + 3n + 2 + 3n \\ -2lmn + 8m & = & -5m + 6n + 2 \\ -2lmn + 8m - 8m & = & -5m + 6n + 2 - 8m \\ -2lmn & = & -13m + 6n + 2 \\ \frac{-2lmn}{-2} & = & \frac{-13m + 6n + 2}{-2} \\ lmn & = & \frac{-13m}{-2} + \frac{6n}{-2} + \frac{2}{-2} \\ lmn & = & \frac{-13m}{-2} + \frac{6n}{-2} - 1 \\ lmn & = & \frac{-13m}{-2} + \frac{3n}{-1} - 1 \\ lmn & = & \frac{-13m}{-2} - 3n - 1 \\ \frac{lmn}{mn} & = & \frac{\frac{-13m}{-2} - 3n - 1}{mn} \\ l & = & \frac{\frac{-13m}{-2} - 3n - 1}{mn} \\ \end{eqnarray} $$ #solve-for-l-03.solution :escaped $$ \begin{eqnarray} -2lmn + 8m - 3n + 9 & = & -5m + 3n - 7 \\ -9 + -2lmn + 8m - 3n + 9 & = & -9 + -5m + 3n - 7 \\ -2lmn + 8m - 3n & = & -9 + -5m + 3n - 7 \\ -2lmn + 8m - 3n & = & -5m + 3n - 7 - 9 \\ -2lmn + 8m - 3n & = & -5m + 3n + -7 + -9 \\ -2lmn + 8m - 3n & = & -5m + 3n + -16 \\ -2lmn + 8m - 3n + 3n & = & -5m + 3n + -16 + 3n \\ -2lmn + 8m & = & -5m + -16 + 6n \\ -2lmn + 8m - 8m & = & -5m + -16 + 6n - 8m \\ -2lmn & = & -13m + 6n + -16 \\ \frac{-2lmn}{-2mn} & = & \frac{-13m + 6n + -16}{-2mn} \\ l & = & \frac{-13m + 6n + -16}{-2mn} \\ l & = & \frac{13m - 6n + 16}{2mn} \\ \end{eqnarray} $$ %h2 Solve for $x$: #solve-for-x-01.solution :escaped $$ \begin{eqnarray} -2xy + 5xz - 5x + 10 & = & -6y - 2 \\ -2xy + 5xz - 5x + 10 - 10 & = & -6y - 2 - 10 \\ -2xy + 5xz - 5x & = & -6y + -2 + -10 \\ -2xy + 5xz - 5x & = & -6y + -12 \\ -2xy + 5xz - 5xz - 5x & = & -6y - 12 - 5xz \\ -2xy - 5x & = & -6y - 12 - 5xz \\ -2xy + 2xy - 5x & = & -6y - 12 - 5xz + 2xy \\ -5x & = & -6y - 12 - 5xz + 2xy \\ \end{eqnarray} $$