2) ab5c=36k, k integer
a*10^3+b*10^2+5*10+c=36k
mod 36 gamu....
28*a+28*b+14+c=0 (mod 36)..........XXX
c =(0,2,4,6,8)...c ta hariyanne mechcharai...
ooka hariyana combination 9k thiyanawa.....check karama...
c=2;,
28*a+28*b+2+14=0 (mod 36)
7*a+7*b+4=0 (mod 9)
-2*a+-2*b+4=0 (mod 9) (7=-2 mod9 nisa)
a=7-b (mod 9)
mekata hariyanne......(a,b,c)=(8,3,2),(7,4,2),(4,7,2),(3,8,2)
c=6;
28*a+28*b+6+14=0 (mod 36)
-2*a-2*b+5=0 (mod 9)
a+b+2=0 (mod 9).....(2^(-1)=5 mod9 nisa)
a=7-b (mod 9)
mekata hariyanne......(a,b,c)=(7,0,6),(7,9,6),(4,3,6),(3,4,6),(9,7,6)
8352,7452,4752,3852,7056,7956,4356,3456,9756
c=0, c=4, c=8 walata a,b, sapuralanne na...XXX
Ithin 9 k thiyanawa sankaya........
Meeta wada sarala kramayak athi......maru gaana.....