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What points are included in the first inequality that may not be included in the second inequality?
See solution.
To draw the inequalities, we must first find their boundary lines.
To draw the boundary lines, we will treat the inequalities as equations.
|c|c|
[-1em]
Inequality & Equation -2pt
[-0.7em]
y≤ 2x-2 & y= 2x-2 -2pt [0.5em]
[-0.7em]
y<2x-2 & y=2x-2 [0.5em]
To complete the graphs we have to shade the correct side of each line. We can do that by testing a point that is not on any of the boundary lines. The easiest point we can choose is the origin. \begin{array}{|c|c|c|} \hline \\[-0.8em] \bm{(x,y)} & \textbf{Inequality} & \textbf{Evaluate} \\[0.2em] \hline \\[-1em] (\col{0},\colII{0}) & \colII{0}\stackrel{?}{\leq}2(\col{0})-2 & \ 0\nleq\N2 \, \Large{\colIII{\times}} \\[0.7em] \hline \\[-1em] (\col{0},\colII{0}) & \colII{0}\stackrel{?}{<}2(\col{0})-2 & \ 0 \nless\N2 \, \Large{\colIII{\times}} \\[0.7em] \hline \end{array} Since the origin produces a false statement for both inequalities, we should shade the side of the lines that does not contain the origin. We end up with the following diagram.
As we can see, the second inequality excludes the boundary line from the solution set whereas the first inequality does not .