Solution:
Consider the following polynomial:
[tex]x^3+4x^2-16x-64[/tex]By grouping terms, we get that the above polynomial is equivalent to the following expression:
[tex](x^3+4x^2)+(-16x-64)[/tex]Now, we can apply common factor:
[tex]x^2(x^{}+4^{})-16(x+4)[/tex]again, applying a common factor, we get:
[tex](x^2-16)(x+4)[/tex]Note that the left factor is a difference of squares, therefore, the above expression is equivalent to:
[tex](x-4)(x+4)(x+4)[/tex]this is equivalent to:
[tex](x-4)(x+4)^2[/tex]So that, we can conclude that the factors of the given expression are:
[tex](x-4)[/tex]and
[tex](x+4)^{2^{}}[/tex]and we can conclude that:
[tex]x^3+4x^2-16x-64=(x-4)(x+4)^2[/tex]