Răspuns:
1+{2·[3+(n-4)·5]:6}·7=8
{2·[3+(n-4)·5]:6}·7=8-1
2·[3+(n-4)·5]:6=7:7
2·[3+(n-4)·5]=1·6
3+(n-4)·5=6:2
(n-4)·5=3-3
n-4=0:5
n=4