SOLUTION: 5x+y=21 4x+3y=8. Solution as an ordered pair?

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Question 1002806: 5x+y=21
4x+3y=8. Solution as an ordered pair?

Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

Solved by pluggable solver: Solve the System of Equations by Graphing



Start with the given system of equations:


5x%2By=21

4x%2B3y=8





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


5x%2By=21 Start with the given equation



1y=21-5x Subtract 5+x from both sides



1y=-5x%2B21 Rearrange the equation



y=%28-5x%2B21%29%2F%281%29 Divide both sides by 1



y=%28-5%2F1%29x%2B%2821%29%2F%281%29 Break up the fraction



y=-5x%2B21 Reduce



Now lets graph y=-5x%2B21 (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+-5x%2B21%29+ Graph of y=-5x%2B21




So let's solve for y on the second equation


4x%2B3y=8 Start with the given equation



3y=8-4x Subtract 4+x from both sides



3y=-4x%2B8 Rearrange the equation



y=%28-4x%2B8%29%2F%283%29 Divide both sides by 3



y=%28-4%2F3%29x%2B%288%29%2F%283%29 Break up the fraction



y=%28-4%2F3%29x%2B8%2F3 Reduce





Now lets add the graph of y=%28-4%2F3%29x%2B8%2F3 to our first plot to get:


+graph%28+600%2C+600%2C+-10%2C+10%2C+-10%2C+10%2C+-5x%2B21%2C%28-4%2F3%29x%2B8%2F3%29+ Graph of y=-5x%2B21(red) and y=%28-4%2F3%29x%2B8%2F3(green)


From the graph, we can see that the two lines intersect at the point (5,-4) (note: you might have to adjust the window to see the intersection)