inmultesti prin 9 si ai :
5* {16+[25-(12:x:2)*9]:8}=90 (acum impartim prin 5 )
16+[25-(12:x:2)*9]:8=18 (scadem 16)
[25-(12:x:2)*9]:8=2 (inmultim prin 8)
25-(12:x:2)*9=16 (scadem 16)
9 -(12:x:2)*9=0 => 9=(12:x:2)*9 (impartim prin 9)
=>1=(12:x:2) => 1=6:x=> x=6
