Next we'll use the power of a power rule in the numerator:
Next we'll simplify using the rule :
Now our expression is:
Now we'll use the rule to divide the x's and y's:
Subtracting the fractions:
which simplify to:
This is a simplified expression. Assuming that the "only positive" in your post means "using only positive exponents" then we have a little more work to do. Using the rule we get:
which simplifies to: