Răspuns:
12k+5=25p+20
12k=25p+15
k=(25p+15)/12EN
k=(24p+12+p+3)/12=2p+1+(p+3)12 EN
p+3 12,p+3 minim=9,Kmin=2p+1+1=20
K=20
p=9
Verificare
12×20+5=25×9+20
240+5=225+20
245=245 Este rezolvata bine problema
a=25p+20 unde p+3=12,24,36...12s
p=12 -3=(9,21,33...)
a=25(12s-3)+20
a=300s-75+20
aa300s-45(se observă ca cel mai mic ,245,verifica relatia)
300s-45<1000
aE(245,245+300,245+600)=245,545,845(