Rewrite the expression using the negative exponent rule .
Rewrite the expression using the negative exponent rule .
Multiply and .
Change the sign of the exponent by rewriting the base as its reciprocal.
Apply the product rule to .
Apply the power rule and multiply exponents, .
Multiply by .
Apply the power rule and multiply exponents, .
Multiply by .
Simplify (a^-5c^-9)^-4