Geometry help! please

alright well i dont understand this problem:

104=1/2[(360 - x) - x]

the directions only say to solve the equation.. PLEASE EXPLAIN THIS TO ME!!!

208 = (360 - x) - x
208 = 360 - 2x
- 152 = - 2x
76 = x

1. Multiply both sides by two to eliminate the 1/2 on the right side of the equation.
208=[(360 - x) - x)]
2. simplify the right side
208=360 - 2x
3. You should have it from here. Subtract 360
-152=-2x
4. Divide by negative 2
X=76

104 = 180 - x => x = 76

all i can tell you is ((360 - x) -x) = 208