SOLUTION: solve the system by graphing: x+y= -5 -2x+y=1

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Question 1075911: solve the system by graphing:
x+y= -5
-2x+y=1
Answer by MathLover1(20849) About Me  (Show Source):
You can put this solution on YOUR website!

x%2By=+-5
-2x%2By=1
--------------------------
Solved by pluggable solver: Solve the System of Equations by Graphing



Start with the given system of equations:


1x%2By=-5

-2x%2By=1





In order to graph these equations, we need to solve for y for each equation.




So let's solve for y on the first equation


1x%2By=-5 Start with the given equation



1y=-5-x Subtract +x from both sides



1y=-x-5 Rearrange the equation



y=%28-x-5%29%2F%281%29 Divide both sides by 1



y=%28-1%2F1%29x%2B%28-5%29%2F%281%29 Break up the fraction



y=-x-5 Reduce



Now lets graph y=-x-5 (note: if you need help with graphing, check out this solver)



+graph%28+600%2C+600%2C+-10%2C+10%2C+-10%2C+10%2C+-x-5%29+ Graph of y=-x-5




So let's solve for y on the second equation


-2x%2By=1 Start with the given equation



1y=1%2B2x Add 2+x to both sides



1y=%2B2x%2B1 Rearrange the equation



y=%28%2B2x%2B1%29%2F%281%29 Divide both sides by 1



y=%28%2B2%2F1%29x%2B%281%29%2F%281%29 Break up the fraction



y=2x%2B1 Reduce





Now lets add the graph of y=2x%2B1 to our first plot to get:


+graph%28+600%2C+600%2C+-10%2C+10%2C+-10%2C+10%2C+-x-5%2C2x%2B1%29+ Graph of y=-x-5(red) and y=2x%2B1(green)


From the graph, we can see that the two lines intersect at the point (-2,-3) (note: you might have to adjust the window to see the intersection)