SOLUTION: Solve the system by the addition (elimination) method. 2x+y=7 3x+y=12

Algebra.Com
Question 187752This question is from textbook
: Solve the system by the addition (elimination) method.
2x+y=7
3x+y=12
This question is from textbook

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 -1.


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.


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 equation below by using the addition (elimination) method: 3x-y=13... (answered by Alan3354,mananth)
Solve the system using the substitution method or the elimination-by-addition method. 2x (answered by solver91311)
Solve the system in Problems using substitution or elimination by addition. 2x y = 7 (answered by Saleye)
solve the following system of equations by the addition method, 2x-7y=2... (answered by stanbon)
Solve the following system by the addition method. 3x-7y= -12 3x+14y= -3 x=... (answered by ewatrrr)
solve each system by the elimination method 1)3x+2y=10 2x+y=7 2)3x-2y=7 2x-y=8 (answered by jojo14344)
Solve each system by the addition method. x + y = 7 X – y = 9 x – y = 12 2x (answered by nerdybill,checkley77)
Solve system by elimination method. 2x-y=12... (answered by mananth)
How do you solve this system by using the elimination method? {2x-y=20... (answered by mathsmiles)