Since 6x and 4x are not in a parentheses, they are not being powered by anything. Therefore, those stay on the numerator side.
Anything to the power of something times another to the power of something is always added together. Since -1 + (-4) is -5, x would end up having a power of -5, which would just make it go on the denominator side with just a power of 5.
Same rule with y follows. This would make it 5+ (-2) = 3. Since this is a positive power, it stays at the numerator side.
