SOLUTION: x=7/2y+4 2x-7y=8 solve by any method

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Question 166684: x=7/2y+4
2x-7y=8
solve by any method
Answer by jim_thompson5910(21684) About Me  (Show Source):
You can put this solution on YOUR website!
Start with the given system
2x-7y=8
x=%287%2F2%29y%2B4



2%28%287%2F2%29y%2B4%29-7y=8 Plug in x=%287%2F2%29y%2B4 into the first equation. In other words, replace each x with 7%2F2y%2B4. Notice we've eliminated the x variables. So we now have a simple equation with one unknown.


2%28%287%2F2%29y%29%2B2%284%29-7y=8 Distribute


7y%2B8-7y=8 Multiply


0y%2B8=8 Combine like terms on the left side.


0y=8-8 Subtract 8 from both sides.


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


0=0 Simplify.


Since this equation is always true for any y value, this means y can equal any number. So there are an infinite number of solutions.