Question 391265
2^(-3)x^(2)z^(-7)

Remove the negative exponent by rewriting 2^(-3)x^(2)z^(-7) as (x^(2)z^(-7))/(2^(3)).  A negative exponent follows the rule a^(-n)=(1)/(a^(n)).
(x^(2)z^(-7))/(2^(3))

Cubing a number is the same as multiplying the number by itself 3 times (2*2*2).  In this case, 2 cubed is 8.
(x^(2)z^(-7))/(8)

Remove the negative exponent in the numerator by rewriting (x^(2)z^(-7))/(8) as (x^(2))/(8(z^(7))).  A negative exponent follows the rule: a^(-n)=(1)/(a^(n)).
(x^(2))/(8(z^(7)))

Remove the negative exponent in the denominator by rewriting (x^(2)z^(-7))/(8) as (x^(2))/(8(z^(7))).  A negative exponent follows the rule: a^(-n)=(1)/(a^(n)).
(x^(2))/(8z^(7))