Final answer:
To simplify the expression (6x^5y^3)^(-2)(7x^4y^9), distribute the exponent -2 to each term inside the parentheses and simplify the expression by combining like terms. The simplified expression is 7/(36x^6y^-6).
Step-by-step explanation:
To simplify the expression (6x5y3)-2(7x4y9), we need to distribute the exponent -2 to each term inside the parentheses. This will result in 6-2x5*-2y3*-2 multiplied by 7x4y9. Simplifying further, we get 1/(62x10y6) multiplied by 7x4y9. Combining the terms, we have 7x4y9/(62x10y6), which can be further simplified as 7/(36x6y-6).