Are there two different ways to express the position operator $x$ in terms of the creation and annihilation operator?

As we known, to express the position operator $x$ in terms of the creation and annihilation operator $a^{+}$ and $a$, one way is:
$$x= sqrt{frac{hbar}{2muomega}}(a^++a);$$

$$p= isqrt{frac{muhbaromega}{2}}(a^+-a).$$

But how about

$$x= -isqrt{frac{hbar}{2muomega}}(a^+-a);$$

$$p= sqrt{frac{muhbaromega}{2}}(a^++a)? $$

I want to know whether the two expressions are fine.

PS: It seems that I can use them to calculate something like fluctuation $langleDelta_xrangle^2$ at coherent state $|alpharangle$.
Both expressions can give the right answer.

By the 1st expression,

$langlealpha|x^2|alpharangle=frac{hbar}{2muomega}[(alpha+alpha^*)^2+1]$,

$langlealpha|x|alpharangle^2=frac{hbar}{2muomega}[(alpha+alpha^*)^2]$

then,

$langleDelta_xrangle^2=langlealpha|x^2|alpharangle – langlealpha|x|alpharangle^2 =frac{hbar}{2muomega}$.

By the 2nd way,

$langlealpha|x^2|alpharangle=-frac{hbar}{2muomega}[(alpha-alpha^*)^2-1]$,

$langlealpha|x|alpharangle^2=-frac{hbar}{2muomega}[(alpha-alpha^*)^2]$

therefore,

$langleDelta_xrangle^2=langlealpha|x^2|alpharangle – langlealpha|x|alpharangle^2 =frac{hbar}{2muomega}$.

The result is the same.

And if we check the dimension, this formula is also OK.