SOLUTION: 4x+y=-1 x+4y=-4

Algebra ->  Graphs -> SOLUTION: 4x+y=-1 x+4y=-4      Log On


   

Question 687954: 4x+y=-1
x+4y=-4
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

4x%2By=-1
x%2B4y=-4
____________________

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



Start with the given system of equations:


4x%2By=-1

1x%2B4y=-4





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


4x%2By=-1 Start with the given equation



1y=-1-4x Subtract 4+x from both sides



1y=-4x-1 Rearrange the equation



y=%28-4x-1%29%2F%281%29 Divide both sides by 1



y=%28-4%2F1%29x%2B%28-1%29%2F%281%29 Break up the fraction



y=-4x-1 Reduce



Now lets graph y=-4x-1 (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+-4x-1%29+ Graph of y=-4x-1




So let's solve for y on the second equation


1x%2B4y=-4 Start with the given equation



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



4y=-x-4 Rearrange the equation



y=%28-x-4%29%2F%284%29 Divide both sides by 4



y=%28-1%2F4%29x%2B%28-4%29%2F%284%29 Break up the fraction



y=%28-1%2F4%29x-1 Reduce





Now lets add the graph of y=%28-1%2F4%29x-1 to our first plot to get:


+graph%28+600%2C+600%2C+-10%2C+10%2C+-10%2C+10%2C+-4x-1%2C%28-1%2F4%29x-1%29+ Graph of y=-4x-1(red) and y=%28-1%2F4%29x-1(green)


From the graph, we can see that the two lines intersect at the point (0,-1) (note: you might have to adjust the window to see the intersection)