SOLUTION: how to solve 2x-5y = 9 -3x+y=-7

Algebra.Com
Question 550712: how to solve 2x-5y = 9
-3x+y=-7

Answer by jim_thompson5910(35256)   (Show Source): You can put this solution on YOUR website!

Start with the given system of equations:



Multiply the both sides of the second equation by 5.


Distribute and multiply.


So we have the new system of equations:



Now add the equations together. You can do this by simply adding the two left sides and the two right sides separately like this:





Group like terms.


Combine like terms.


Simplify.


Divide both sides by to isolate .


Reduce.


------------------------------------------------------------------


Now go back to the first equation.


Plug in .


Multiply.


Subtract from both sides.


Combine like terms on the right side.


Divide both sides by to isolate .


Reduce.


So the solutions are and .


Which form the ordered pair .


This means that the system is consistent and independent.


Notice when we graph the equations, we see that they intersect at . So this visually verifies our answer.


Graph of (red) and (green)

RELATED QUESTIONS

Solve the system using the substituion method. 2x - 5y = 9 -3x + y =... (answered by AnlytcPhil)
Using Substitution to Solve Linear Systems of Equations 1. y= x -1 2x -y =0 2. x+y=... (answered by checkley71)
How to solve 1. 2x+3y=13 3x+5y=40 2. 3x+5y=7... (answered by Cromlix)
Please help me solve these equations: 4(x-3y)+2(3x-y)+y, 9(-3x+5y-7(x+6y), and... (answered by ReadingBoosters)
3x+5y-Z=-3, 2x+y-3z=-9, x+3y+2z=7 to where x,y... (answered by Fombitz)
How would I solve these systems? 1)x+5y=4 3x-7y=-10 2)-5x+3y=6 x-y=4 (answered by elima)
how do you solve 8x-5y=9 y=2x-4 (answered by lynnlo)
How do you solve this system using elimination? -2x+5y-3z=7 4x-3y+2z=4... (answered by t0hierry,greenestamps)
How do i slove the system 2x-5y=9 and -3x+y=-7 using the substitution... (answered by colliefan)