x=nr.elevi
1200>x>1000
x:6=a,r=5=>x=6a+5=>x-5=6a
x:7=b,r=5=>x=7b+5=>x-5=7b
x:8=c,r=5=>x=8c+5=>x-5=8c
x:9=d,r=5=>x=9c+5=>x-5=9d
Din amanpatru => x-5=[6,7,8,9]
x-5=504 K
1200>x>1000
1195>x-5>995
1195<504k>995
2 intregi 187/504<k<1 intreg 491/504
K ∈ Z
Din ambele rezulta=>K=2
x-5=2*504
x-5=1008
x=1013