Answer:
81m^6 - 323 m^5 + 432m^4 - 192m^3
Explanation:
Comment
If you are given choices, you should list them please. Otherwise we cannot be certain our answers are taken far enough.
The general formula for expanding a binomial raised to the third power is
(a - b)^3 = a^3 - 3a^2b + 3ab^2 - b^3
Solution
To modify the general formula to suit this problem, let
a = 3m
b = - 4
When that is done, the general equation becomes
(3m)^3 - 3* (3m)^2 * 4 + 3 * 3m * 4^2 - 4^3
(3m - 4)^3 = 27m^3 - 108 m^2 + 144m - 64
Multiply everything in the 4-nomial by 3m^3
(27m^3 - 108 m^2 + 144m - 64)3m^3
81m^6 - 323 m^5 + 432m^4 - 192m^3 which is your answer. I see why you didn't include it, with other (incorrect) possibilities.