SOLUTION: Graph the system of equations on your graph paper to answer the question. {y=-3x+9, y=-x-5 What is the solution for the system of equations? Enter your answer i

Algebra ->  Coordinate Systems and Linear Equations  -> Lessons -> SOLUTION: Graph the system of equations on your graph paper to answer the question. {y=-3x+9, y=-x-5 What is the solution for the system of equations? Enter your answer i      Log On


   

Question 1109722: Graph the system of equations on your graph paper to answer the question.

{y=-3x+9, y=-x-5

What is the solution for the system of equations?
Enter your answer in the boxes.

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


y=-3x%2B9
y=-x-5
write the two equations in standard form Ax%2BBy=C:
3x%2By=9
x%2By=-5
Solved by pluggable solver: Solve the System of Equations by Graphing



Start with the given system of equations:


3x%2By=9

1x%2By=-5





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


3x%2By=9 Start with the given equation



1y=9-3x Subtract 3+x from both sides



1y=-3x%2B9 Rearrange the equation



y=%28-3x%2B9%29%2F%281%29 Divide both sides by 1



y=%28-3%2F1%29x%2B%289%29%2F%281%29 Break up the fraction



y=-3x%2B9 Reduce



Now lets graph y=-3x%2B9 (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+-3x%2B9%29+ Graph of y=-3x%2B9




So let's solve for y on the second 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 add the graph of y=-x-5 to our first plot to get:


+graph%28+600%2C+600%2C+-10%2C+10%2C+-10%2C+10%2C+-3x%2B9%2C-x-5%29+ Graph of y=-3x%2B9(red) and y=-x-5(green)


From the graph, we can see that the two lines intersect at the point (7,-12) (note: you might have to adjust the window to see the intersection)