Question

6a(3b^{2}-4b - 9)+24ab

Explanation:

Step1: Distribute 6a

$6a\times3b^{2}-6a\times4b - 6a\times9+24ab$
$= 18ab^{2}-24ab - 54a+24ab$

Step2: Combine like - terms

$18ab^{2}+(-24ab + 24ab)-54a$
$=18ab^{2}-54a$

Answer:

$18ab^{2}-54a$