[ ( 3 + a : 2 ) : 11 + 7 ] × 5 - 8 = 41
[ ( 3 + a : 2 ) : 11 + 7 ] × 5 = 41 + 8
[ ( 3 + a : 2 ) : 11 + 7 ] × 5 = 49
( 3 + a : 2 ) : 11 + 7 = 49 : 5
( 3 + a : 2 ) : 11 + 7 = 9, 8
( 3 + a : 2 ) : 11 = 9, 8 - 7
( 3 + a : 2 ) : 11 = 2, 8
3 + a : 2 = 2, 8 × 11
3 + a : 2 = 30, 8
a : 2 = 30, 8 - 3
a : 2 = 27, 8
a = 27, 8 × 2
a = 55, 6
