Question 607587
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Can't say what the teacher is doing wrong, if anything. *[tex \LARGE x\ =\ 2] and *[tex \LARGE y\ =\ 1] is correct, and given error free arithmetic should be the result of any solution method:  Substitution, Elimination, Gauss-Jordan Row Reduction, and/or Cramer's Rule.  Which is the case; I checked.

The problem could be that the teacher has specified a way of presenting the solution.  I.e. s/he may want the answer in ordered pair form or perhaps even in solution set form:

Ordered pair:

*[tex \LARGE \ \ \ \ \ \ \ \ \ \ (2,\,1)]

Solution set

*[tex \LARGE \ \ \ \ \ \ \ \ \ \ \left{(2,\,1)\right}]

Then again, it wouldn't be the first time that a teacher, textbook, and/or answer key was wrong.  Won't be the last time either.

John
*[tex \LARGE e^{i\pi}\ +\ 1\ =\ 0]
My calculator said it, I believe it, that settles it
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