x-numarul
{[(x:4)-309]×100+1000}:1000+1976=1996
{[(x:4)-309]×100+1000}=(1996-1976)×1000
[(x:4)-309]×100=20×1000-1000
[(x:4)-309]×100=19000
(x:4)-309=19000:100
x:4=190+309
x:4=499
x=499×4
x=1996
p:
1996:4=499
499-309=190
190×100=19000
19000+1000=20000
20000:1000=20
20+1976=1996