{[( a × 9 ) : 3 ] × 4 } : 5 - 6 = 6
{[( a × 9 ) : 3 ] × 4 } : 5 = 6 + 6
{[( a × 9 ) : 3 ] × 4 } : 5 = 12
[( a × 9 ) : 3 ] × 4 = 12 × 5
[( a × 9 ) : 3 ] × 4 = 60
( a × 9 ) : 3 = 60 : 4
( a × 9 ) : 3 = 15
a × 9 = 15 × 3
a × 9 = 45
a = 45 : 9
a = 5
SPER CA TE-AM AJUTAT!