Question

Multiply -9ab exponent 5 (a with exponent 2 b with the exponent 4 - 10a with the exponent 3 then b plus 5 ab -3)

Answer 1

The term -9ab^5 multiplies every term inside the brackets. The multiplication of the same variables implies a "sum" of its exponent.

$-9ab^5(a^2b^4-10a^3b+5ab-3)=-9a^3b^9+90a^4b^6-45a^2b^6+27ab^5$