15/8 is already an improper fraction, if you want a proper fraction the answer is 1 and 7/8
81 because 81 is a perfect square and 27 times 3 =81
It would seem that the 25% down and 25% increase would cancel each other out and the shoes would remain $60
2x+3y=6
subtract 2x from both sides.
3y=6-2x
divide by 3 on all sides.
y=2-2/3x
