Question

(a-2b+3c)(ab^2-a^2b)

Answer 1

ab • (ab - a - 2b2 + 3bc) is your answer
(a • (a - 2b + 3c) • b2) - a2b
= ab2 • (a - 2b + 3c) - a2b
= 4.1     Pull out like factors :

   a2b2 - a2b - 2ab3 + 3ab2c  = 

  ab • (ab - a - 2b2 + 3bc) 
the final result is ab • (ab - a - 2b2 + 3bc)

Answer 2

(a-2b+3c)(ab^2-a^2b)
= (a-2b+3c)(ab)(b-a)
= (ab)(a-2b+3c)(b-a)
= (ab)(ab-2b^2+3bc-a^2+2ab-3ac)
= (ab)(-a^2-2b^2+3ab+3bc-3ac)