Question

Simplify.

(2a^2-9b)(4a+b)

A. 8a^3+36a^2b-2ab-9b^2
B. 8a^3+2a^2b-36ab-9b^2
C. 8a^3-34ab-9b^2
D. 8a^3-9b^2

Answer 1

B.)8a^3+2a^2b-36ab-9b^2

(2a^2-9b)(4a+b)

Use the distributive property of multiplication.

4a(2a^2-9b)+b(2a^2-9b)

Expand.

8a^3-36ab+2a^2b-9b^2

Put in neater order, so that powers are consecutive (i.e putting x^2 after x^3)

8a^3+2a^2b-36ab-9b^2