SOLUTION: Use elimination method in solving this:tnx 4x-y=8 2x+y=4

Algebra ->  Coordinate Systems and Linear Equations -> SOLUTION: Use elimination method in solving this:tnx 4x-y=8 2x+y=4      Log On


   

Question 183268: Use elimination method in solving this:tnx
4x-y=8
2x+y=4
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

Start with the given system of equations:
system%284x-y=8%2C2x%2By=4%29


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


%284x-y%29%2B%282x%2By%29=%288%29%2B%284%29


%284x%2B2x%29%2B%28-y%2By%29=8%2B4 Group like terms.


6x%2B0y=12 Combine like terms.


6x=12 Simplify.


x=%2812%29%2F%286%29 Divide both sides by 6 to isolate x.


x=2 Reduce.


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


4x-y=8 Now go back to the first equation.


4%282%29-y=8 Plug in x=2.


8-y=8 Multiply.


-y=8-8 Subtract 8 from both sides.


-y=0 Combine like terms on the right side.


y=%280%29%2F%28-1%29 Divide both sides by -1 to isolate y.


y=0 Reduce.


So the solutions are x=2 and y=0.


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 4x-y=8 (red) and 2x%2By=4 (green)