SOLUTION: Hi, I have tried and tried to answer the following problem - it involves three variables and using substitution: 5x -y = 7 y = 5x + 6 If I plug in (5x + 6) as y into the fi

Algebra ->  Expressions-with-variables -> SOLUTION: Hi, I have tried and tried to answer the following problem - it involves three variables and using substitution: 5x -y = 7 y = 5x + 6 If I plug in (5x + 6) as y into the fi      Log On


   



Question 159222: Hi,
I have tried and tried to answer the following problem - it involves three variables and using substitution:
5x -y = 7
y = 5x + 6
If I plug in (5x + 6) as y into the first equation, the x's cancel each other out, leaving me with 0 instead of a variable (I have tried a bunch of different ways, and all cancel out the variable - my mom has tried as well). Is the solution "no solution?"
I have a test on substitution tomorrow, so any help would be greatly appreciated.
Thank you!

Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
I have tried and tried to answer the following problem - it involves three variables and using substitution:
5x -y = 7
y = 5x + 6
If I plug in (5x + 6) as y into the first equation, the x's cancel each other out, leaving me with 0 instead of a variable (I have tried a bunch of different ways, and all cancel out the variable - my mom has tried as well). Is the solution "no solution?"
I have a test on substitution tomorrow, so any help would be greatly appreciated.
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Rearrange the 2nd eqn:
5x -y = 7
5x -y = -6
These can't both be true, 7 <> -6, so: NO Solution.
If you graph the 2 eqns, you'll see they're 2 parallel lines.