SOLUTION: 5x+2y=-1 3x+7y=11

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Question 701289: 5x+2y=-1
3x+7y=11
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

5x%2B2y=-1.......1
3x%2B7y=11........2
___________________

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



Start with the given system of equations:


5x%2B2y=-1

3x%2B7y=11





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%2B2y=-1 Start with the given equation



2y=-1-5x Subtract 5+x from both sides



2y=-5x-1 Rearrange the equation



y=%28-5x-1%29%2F%282%29 Divide both sides by 2



y=%28-5%2F2%29x%2B%28-1%29%2F%282%29 Break up the fraction



y=%28-5%2F2%29x-1%2F2 Reduce



Now lets graph y=%28-5%2F2%29x-1%2F2 (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+%28-5%2F2%29x-1%2F2%29+ Graph of y=%28-5%2F2%29x-1%2F2




So let's solve for y on the second equation


3x%2B7y=11 Start with the given equation



7y=11-3x Subtract 3+x from both sides



7y=-3x%2B11 Rearrange the equation



y=%28-3x%2B11%29%2F%287%29 Divide both sides by 7



y=%28-3%2F7%29x%2B%2811%29%2F%287%29 Break up the fraction



y=%28-3%2F7%29x%2B11%2F7 Reduce





Now lets add the graph of y=%28-3%2F7%29x%2B11%2F7 to our first plot to get:


Graph of y=%28-5%2F2%29x-1%2F2(red) and y=%28-3%2F7%29x%2B11%2F7(green)


From the graph, we can see that the two lines intersect at the point (-1,2) (note: you might have to adjust the window to see the intersection)