SOLUTION: x=-4y 3x+2y=20

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Question 118576: x=-4y
3x+2y=20
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
Start with the given system
3x%2B2y=20
x=-4y



3%28-4y%29%2B2y=20 Plug in x=-4y into the first equation. In other words, replace each x with -4y. Notice we've eliminated the x variables. So we now have a simple equation with one unknown.


-12y%2B2y=20 Multiply


-10y=20 Combine like terms on the left side


y=%2820%29%2F%28-10%29 Divide both sides by -10 to isolate y



y=-2 Divide




Now that we know that y=-2, we can plug this into x=-4y to find x



x=-4%28-2%29 Substitute -2 for each y


x=8 Simplify


So our answer is x=8 and y=-2