1/2(n - 4) - 3 = 3 - (2n + 3)
Distribute the 1/2 and the negative sign.
1/2n - 2 - 3 = 3 + (-2n) - 3
Subtract the -2 and 3
1/2n - 5 = 3 + (-2n) - 3
Add the 3's
1/2n - 5 = -2n
Add 2n to both sides
5/2n − 5 = 0
Add 5 to both sides
5/2n = 5
Multiply both sides by 2/5
n = 2