To solve this, we simply need to remember our rules about order of operations. They tell us that first, we should distribute the 2 with the rest of the parentheses.
5-2(x-3)
5-2x+6
Next, we should combine our like-terms.
5-2x+6
11-2x
Seeing as we do not know the value of the variable, the simplest form of the expression is 11-2x.