x is a variable.
x can be anything, such as 1, or 2, or even 50.
Saying x2 simply means you are taking x and multiplying it by 2.
So if x was 3, x2 would be 6.
Or if x was 7, x2 would be 14.
It's preferred to write it as 2x, though, with the algebraic variable written after the coefficient (ordinary number).
