Okay. I think the fractions in the matrix are what freaked me out about this problem. I didn't realize substitution could be applied here to simplify the matrix so quickly. After solving, I got the same results as you: (x,y)=(3,1/2). Converting it back to the original fractions with those answers looks much easier than before, and significantly less scary!
Since I'm dealing with fractions again, I made both sides into fractions.. . . . .
Then cross multiplication gets me:. . . . .. . . . .. . . . .. . . . .
Solving for Y (sparing the details):. . . . .
So my final answer is:. . . . .
After that I have some bad news. I got that quiz question wrong!
But now I understand it for the big test! Thank you Liz!