When there is a negative to the power of x, it makes it a 1/x to that power. (X^-5 becomes 1/x^5)
For two x’s to a power in a fraction (x^6/x^7), you subtract the greatest x power by the least x power. So, it will become 1/x (7-6=1, the six up top disappears but you still need the x on the bottom as it did not disappear, which is where the 1 comes from)
Hopefully I explained it clearly enough and this can help you :)