I have the square trinomial

$\displaystyle 25 - 10x + x^2$

If I factor it I get:

$\displaystyle (5 - x)^2$

but If I rearrange the addends in an order in which literal addend are to precede numerial addends,

$\displaystyle x^2 -10x + 25$,

and factor it I get:

$\displaystyle (x-5)^2$

aren't $\displaystyle 25 - 10x + x^2$ and $\displaystyle x^2 -10x + 25$ equal in value?

Why do I get different square binomials?