SOLUTION: How do you solve a problem using substitution if you have no kown variables. Question is: x-2y=3 4x-8y=12

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Question 710295: How do you solve a problem using substitution if you have no kown variables.
Question is:
x-2y=3
4x-8y=12

Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!


Solve one of the equations for one of the variables in terms of the other. For example is equivalent to .

Then substitute the expression in for in the second equation.



Solve the resulting single variable equation. You will either get a single answer which you then substitute back in to either of the original equations, or...

You will get a triviality, such as . This means that the solution set of the system has infinite elements, or...

You will get an absurdity, such as . This means that the solution set of the system is the empty set.

John

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