SOLUTION: solve the system of equations using the addition (elimination) method. If the answer is a unique solution, present it as an ordered pair: (x, y). If not, specify whether the answe

Algebra ->  Coordinate Systems and Linear Equations  -> Lessons -> SOLUTION: solve the system of equations using the addition (elimination) method. If the answer is a unique solution, present it as an ordered pair: (x, y). If not, specify whether the answe      Log On


   

Question 161753: solve the system of equations using the addition (elimination) method.
If the answer is a unique solution, present it as an ordered pair: (x, y). If not, specify whether the answer is “no solution” or “infinitely many solutions.”
x + 2y = 5
3x + 4y = 1
Answer by elima(1433) About Me  (Show Source):
You can put this solution on YOUR website!
You will add the equations together in order to eliminate one of the variables;
x + 2y = 5
3x + 4y = 1
Lets start by eliminating the y, so we will multiply the first equation by -2;
-2 (x + 2y = 5)
-2x - 4y = -10
Now we will be able to add the two equations together so we can eliminate the y;
-2x-4y =-10
3x + 4y = 1
-----------
x= -11
Now plug the -11 in either equation for x;
-11 + 2y = 5
2y = 5+11
2y = 16
y=8
so the answer is;
(-11, 8)
:)