Answer:
To simplify the expression, we can use the laws of exponents and simplify each term separately:
(a^-2c^9)^-3 / (ab)^-5 c^-7 × a/b^-3 c^-1
= (c^9/a^2)^-3 / a^-5b^-5 c^-8 × a/b^-3 c^-1
= (a^6c^-27) / (b^2c^-9a^-5) × (ab^3c)
= a^(6-5+1) b^(-2+3) c^(-27-(-9)-1)
= a^2 b c^-17
Therefore, x = 2, y = 1, and z = -17.