To simplify this expression, we first need to combine like terms and simplify any terms inside parentheses.

The expression x+3/1-x*(x/x-3+3-x/x+3) can be simplified as follows:

Combine the terms inside the parentheses:
(x/x - 3) + (3 - x/x + 3) becomes (1 - 3) + (3 - 1) = -2 + 2 = 0

Substitute the simplified value back into the expression:
x + 3 / 1 - x*(0)

Simplify further by multiplying:
x + 3 / 1 - 0
x + 3 / 1

Therefore, the simplified expression is x + 3 / 1.