Question 225320
How do I solve and graph for x intercept and y intercept the following equation: y = -x ?   Thanks!!


Step 1.  The slope-intercept form is given as y=mx+b where m is the slope and b is the y-intercept when x=0 or at point (0,b).


Step 2.  Comparing {{{y=-1}}} with  {{{y=mb+b}}} we have the slope m=-1 and b=0.


Step 3.  To graph to get the y-intercept we set x=0 and in this case y=b=0.


Step 4.  To get the x-intercept we set y=0 and again in this case x=0.  So we have (0,0) as a point.   Since the x-intercept and y-intercept are the same then we need another point.  Say at x=1 then y=-1 so (1,-1) is a point on the line.  We can use these two points (0,0) and (1,-1) to plot the line.


Step 5.  Another way to graph:  With the slope m=-1 then for every unit you go to the right you go one unit down.  You get the same result (1,-1) or from (1,-1) you get (2,-2) as another point on the line.


Step 6.  Here's the graph,


{{{graph(400,400,-5,5,-5, 5, -x)}}}


I hope the above steps were helpful.


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Respectfully,
Dr J

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