Question 374739
{{{x+y=1}}} 
{{{y=-x+1}}} 
{{{highlight(y=-x+1)}}} 
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{{{drawing(300,300,-6,6,-6,6,grid(1), graph(300,300, -6,6,-6,6, 0,-x+1))}}}
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{{{3x-y=15}}}
{{{-y=-3x+15}}}
{{{highlight(y=3x-15)}}}
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{{{drawing(300,300,-6,6,-6,6,grid(1), graph(300,300,-6,6,-6,6,0,-x+1,3x-15))}}}
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