SOLUTION: Graph 3x+4y=-12

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Question 209747: Graph 3x+4y=-12
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

3x%2B4y=-12 Start with the given equation.


4y=-12-3x Subtract 3x from both sides.


4y=-3x-12 Rearrange the terms.


y=%28-3x-12%29%2F%284%29 Divide both sides by 4 to isolate y.


y=%28%28-3%29%2F%284%29%29x%2B%28-12%29%2F%284%29 Break up the fraction.


y=-%283%2F4%29x-3 Reduce.




Looking at y=-%283%2F4%29x-3 we can see that the equation is in slope-intercept form y=mx%2Bb where the slope is m=-3%2F4 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%2F4, this means:

rise%2Frun=-3%2F4


which shows us that the rise is -3 and the run is 4. This means that to go from point to point, we can go down 3 and over 4



So starting at , go down 3 units


and to the right 4 units to get to the next point



Now draw a line through these points to graph y=-%283%2F4%29x-3

So this is the graph of y=-%283%2F4%29x-3 through the points and