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Printjmc
algebra intermediate
Problem
Find all real numbers such that
Solution
We expand the left-hand side and then subtract from both sides, giving or Factoring top and bottom gives Letting denote the left-hand side, we produce a sign table as follows: \begin{array}{c|ccc|c} &$5x-3$ &$7x-3$ &$(2x-1)^2$ &$f(x)$ \\ \hline$x<\frac{3}{7}$ &$-%%DISP_0%%amp;$-%%DISP_0%%amp;$+%%DISP_0%%amp;$+$\\ [.1cm]$\frac{3}{7}<x<\frac{1}{2}$ &$-%%DISP_0%%amp;$+%%DISP_0%%amp;$+%%DISP_0%%amp;$-$\\ [.1cm]$\frac{1}{2}<x<\frac{3}{5}$ &$-%%DISP_0%%amp;$+%%DISP_0%%amp;$+%%DISP_0%%amp;$-$\\ [.1cm]$x>\frac{3}{5}$ &$+%%DISP_0%%amp;$+%%DISP_0%%amp;$+%%DISP_0%%amp;$+$\\ [.1cm]\end{array}We see that when or Also, when or Hence, the solution set to is
Final answer
(-\infty, \tfrac37] \cup [\tfrac35, \infty)