SOLUTION: Solve the system by substitution 2x+2y=0 y=4x+0

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Question 125686: Solve the system by substitution
2x+2y=0
y=4x+0
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

Start with the given system
2x%2B2y=0
y=2x



2x%2B2%282x%29=0 Plug in y=2x into the first equation. In other words, replace each y with 2x. Notice we've eliminated the y variables. So we now have a simple equation with one unknown.


2x%2B4x=0 Multiply


6x=0 Combine like terms on the left side


x=%280%29%2F%286%29 Divide both sides by 6 to isolate x



x=0 Divide




Now that we know that x=0, we can plug this into y=2x to find y



y=2%280%29 Substitute 0 for each x


y=0 Simplify


So our answer is x=0 and y=0 which also looks like



Notice if we graph the two equations, we can see that their intersection is at . So this verifies our answer.


+graph%28+500%2C+500%2C+-5%2C+5%2C+-5%2C+5%2C+-x%2C+2x%29+ Graph of 2x%2B2y=0 (red) and y=2x (green)