SOLUTION: I have already passed algebra but didn't pass the EOC and have forgotten alot of information. But anyway one of my questions is using substituion and elimination. x-11y=-123 11x

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Question 247206: I have already passed algebra but didn't pass the EOC and have forgotten alot of information. But anyway one of my questions is using substituion and elimination. x-11y=-123 11x-y=-33 i forget where and how to start. could you please help me??
Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!


Substitution Method: Solve one of your equations for one of the variables in terms of the other, then substitute the expression for the chosen variable into the second equation. Thus:

Equation 1:

Equation 2:

Add 11y to both sides of Equation 1:



Substitute into Equation 2:



Now just simplify and solve for . Once you have the value of , substitute that back into either equation and solve for .

Elimination Method: Multiply one or both equations by some value that makes the coefficient on one of the variables equal to the additive inverse of that same variable's coefficient in the other equation. Then add the equations term-by-term. The coefficient of the chosen variable in the sum will be zero, eliminating (hence the name of the method) that variable and leaving you with a single equation in a single variable that can be solved by ordinary means. Thus:

Equation 1:

Equation 2:

Multiply Equation 2 by -11:

Equation 3:

Add Equation 3 to Equation 1, term-by-term:

Equation 4:

Notice that the term has been eliminated.

Now all you have to do is solve:

Equation 4:

And then substitute the calculated value for back into either of the original equations and solve the result for .

Let me know what you come up with.

John