Question 106863
{{{y=(1/2)x-1}}} Start with the given equation



Let's test the first solution (-1,2):



{{{(2)=(1/2)(-1)-1}}} Plug in {{{x=-1}}} and  {{{y=2}}}



{{{2=-1.5}}} Simplify. Since the two sides of the equation are <font size=4><b>not</b></font> equal, this means (-1,2) is <font size=4><b>not</b></font> a solution to {{{y=(1/2)x-1}}}



Now let's graph the equation {{{y=(1/2)x-1}}} and plot the points (-1,2)

{{{drawing(900,900,-10,10,-10,10,
graph(900,900,-10,10,-10,10,1/2*x-1),

circle(-1,2,0.08),
circle(-1,2,0.10))}}}



Notice the point is <font size=4><b>not</b></font> on the line. So this shows that (-1,2) is <font size=4><b>not</b></font> a solution to {{{y=(1/2)x-1}}}