simplify the expression. (9x^4y^5)(- 2x^2y^7)
When multiplying expressions with the same base, you can add the exponents.
So, (9x^4y^5)(- 2x^2y^7) simplifies to 9(-2)x^(4+2)y^(5+7).
The simplified expression is -18x^6y^12.
So, (9x^4y^5)(- 2x^2y^7) simplifies to 9(-2)x^(4+2)y^(5+7).
The simplified expression is -18x^6y^12.