rearanging

V^2 = Vo^2 + 2 a (X - Xo)

for V gives me

V = (Vo^2 + 2 a (X - Xo))^(2^-1)

or this

V = (Vo + 2 a (X - Xo))^(2^-1)

How come Vo^2 dosen't become Vo

It is rather unusual to write 2^-1 for 1/2, but either is OK.

Vo^2 is not V^2 because the equation says that it isn't. The reasons are due to physics. Velocity decreases when there is deceleration.

Vo^2 can never become V. They have different dimensions. One is squared and the other isn't.

I didn't right Vo^2 as V...

This is what you wrote:

<<How come Vo^2 dosen't become Vo >>

I agree and as you can see I wrote "...Vo^2 dosen't become Vo"

not

""...Vo^2 dosen't become V"

V^2 = Vo^2 + 2 a (X - Xo)

V= sqrt ( Vo^2 + 2 a (X - Xo)

Your algebra is totally wrong.

The initial speed squared Vo^2 is in meters^2/seconds^2

The final speed V is in meters/second
They can never, ever be the same as drwls said.

Nor can Vo^2 be Vo for the same reason.