To expand this expression, we can use the distributive property.

First, distribute $х-4$ into ${х}^2+4x+16$:
$х$${х}^2$ + $х$$4x$ + $х$$16$ + $-4$${х}^2$ + $-4$$4x$ + $-4$$16$ + 28

This simplifies to:
х^3 + 4х^2 + 16х - 4х^2 - 16x - 64 + 28

Now combine like terms:
х^3 + 16х - 36

So, the expanded form of $х-4$${х}^2+4x+16$ + 28 is х^3 + 16х - 36.