n+(n+8)+((n+8)-4)=24*3
n+n+8+n+8-4=72
3n+12=72
3n=60
n=20-1кл
n+8=20+8=28-2кл
(n+8)-4=28-4=24кл
20+28+24=24*3
72=72
n+(n+8)+((n+8)-4)=24*3
n+n+8+n+8-4=72
3n+12=72
3n=60
n=20-1кл
n+8=20+8=28-2кл
(n+8)-4=28-4=24кл
20+28+24=24*3
72=72