1/2 (4-n)-1/3 (1+n)=1/4

2-1/2n-1/3-1/3n=1/4
5/3-3/6n-2/6n=1/4
-5/6n = 1/4-5/3
-5/6n = 3/12-20/12
-5/6n = – 17/12
-10n = -17
n = 17/10 = 1,7