If two things are equal to each other, then you can substitute one for the other any time you like.
Your second equation sets equal to
So you can substitute the expression for whereever it is convenient to do so -- at least within the context of this problem.
That means that you can re-write your first equation thusly:
resulting in an equation in a single variable that can be solved by ordinary means. Once you have determined the value of , that value can be substituted back into either equation so as to be able to calculate the value of .
Now that you have a value for and a value for , you can create an ordered pair which is the single element of the solution set of the 2X2 system of equations.
If you have already done all of that and are bothered by the fact that the values of and are rather ugly fractions, remember that no one has ever given you a written guarantee that the answers to math problems would always turn out to be nice neat round numbers or fractions with single digit denominators.
John
My calculator said it, I believe it, that settles it
