SOLUTION: what steps would you use to graph the equation 3x-7y=21?

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Question 281614: what steps would you use to graph the equation 3x-7y=21?
Found 2 solutions by jim_thompson5910, Alan3354:
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
3x-7y=21 Start with the given equation.


-7y=21-3x Subtract 3x from both sides.


-7y=-3x%2B21 Rearrange the terms.


y=%28-3x%2B21%29%2F%28-7%29 Divide both sides by -7 to isolate y.


y=%28%28-3%29%2F%28-7%29%29x%2B%2821%29%2F%28-7%29 Break up the fraction.


y=%283%2F7%29x-3 Reduce.


Looking at y=%283%2F7%29x-3 we can see that the equation is in slope-intercept form y=mx%2Bb where the slope is m=3%2F7 and the y-intercept is b=-3


Since b=-3 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%2F7, this means:

rise%2Frun=3%2F7


which shows us that the rise is 3 and the run is 7. This means that to go from point to point, we can go up 3 and over 7



So starting at , go up 3 units


and to the right 7 units to get to the next point



Now draw a line through these points to graph y=%283%2F7%29x-3

So this is the graph of y=%283%2F7%29x-3 through the points and

Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
It's a straight line, so I'd find 2 points.
Pick values for x and find y, or vice versa.
Plot the 2 points.
Draw a line thru them.
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I'd use the x and y intercepts.
Let x=0, find y.
Let y=0, find x.