1) (1-m)(m^2+4m) = 1•m^2 + 4•m - m•m - 4•m = m^2 + 4m - m^2 - 4m = 0
2) (a-4b)(a^2-3ab+2b^2) = a•a^2 - 3•a•a•b + 2•a•b^2 - 4•b•a^2 + 12•b•a•b - 8•b•b^2= a^3 - 3a^2b + 2ab^2 - 4a^2b + 12ab^2 - 8b^3= a^3 - 7a^2b + 14ab^2 - 8b^3
1) (1-m)(m^2+4m) = 1•m^2 + 4•m - m•m - 4•m = m^2 + 4m - m^2 - 4m = 0
2) (a-4b)(a^2-3ab+2b^2) = a•a^2 - 3•a•a•b + 2•a•b^2 - 4•b•a^2 + 12•b•a•b - 8•b•b^2
= a^3 - 3a^2b + 2ab^2 - 4a^2b + 12ab^2 - 8b^3
= a^3 - 7a^2b + 14ab^2 - 8b^3