Answer:
1/x^24
Step-by-step explanation:
(x^-6/x^2)^3 multiply the powers inside the parenthesis by power outside of the parenthesis to get rid of parenthesis
x^-6×3/x^2×3 = x^-18/x^6
subtract the denominator's power from nominator's power
x^-18-6 = x^-24 ➡ 1/x^24
