SOLUTION: please help me graph this equation 3x-y=9 thank you

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Question 128883: please help me graph this equation 3x-y=9 thank you
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

3x-y=9 Start with the given equation


-y=9-3x Subtract 3+x from both sides


-y=-3x%2B9 Rearrange the equation


y=%28-3x%2B9%29%2F%28-1%29 Divide both sides by -1


y=%28-3%2F-1%29x%2B%289%29%2F%28-1%29 Break up the fraction


y=3x-9 Reduce





Looking at y=3x-9 we can see that the equation is in slope-intercept form y=mx%2Bb where the slope is m=3 and the y-intercept is b=-9


Since b=-9 this tells us that the y-intercept is .Remember the y-intercept is the point where the graph intersects with the y-axis

So we have one point




Now since the slope is comprised of the "rise" over the "run" this means
slope=rise%2Frun

Also, because the slope is 3, this means:

rise%2Frun=3%2F1


which shows us that the rise is 3 and the run is 1. This means that to go from point to point, we can go up 3 and over 1



So starting at , go up 3 units


and to the right 1 unit to get to the next point



Now draw a line through these points to graph y=3x-9

So this is the graph of y=3x-9 through the points and