There are dozens of paths you could follow to simplify an expression like this....
Since all of the variables occur only once each, I would simplify the expression in one step by considering each variable separately.
Specifically, I would "distribute" the -1 exponent on the expression in parentheses to each factor inside the parentheses; then if the resulting exponent is positive I would leave that factor where it is (numerator or denominator), and if the resulting exponent is negative I would move that factor to the other part of the fraction.
2 in the numerator: the exponent is 1; multiplied by -1 is -1; the 2 moves to the denominator
p^-7 in the numerator: -7 times -1 is +7; the p^7 stays in the numerator
z^3 in the numerator: 3 times -1 is -3; the z^3 moves to the denominator
3 in the denominator: the exponent is 1; multiplied by -1 is -1; the 3 moves to the numerator
q^-2 in the denominator: -2 times -1 is +2; the q^2 stays in the denominator
x^-4 in the denominator: -4 times -1 is +4; the x^4 stays in the denominator
My result is p^7, 3, q^2, and x^4 in the numerator, and 2 and z^3 in the denominator:
