Question 236881
64m^3+125n^3

We have the sum of cubes.

The sum of cubes formula is a^3 + b^3 = (a + b)(a^2 – ab + b^2)

64 can be written as 4^3 and 125 can be written as 5^3.

In the formula above, let a = 4m and b = 5n.

4m^3 + 5n^3 = (4m + 5n)(4m^2 – 4*5mn + 5m^2)

4m^3 + 5n^3 =  (4m + 5n)(16m^2 – 20mn + 25m^2)

You did great but forgot to include the other factor, which is (4m + 5n).

You also forgot that the middle term is positive not negative for the sum of cubes.

Otherwise, good job!

Final answer:

64m^3 + 125n^3 = (4m + 5n)(16m^2 – 20mn + 25m^2)