8 + 6 × [ 4 + 27 : ( 0 + b × 9 ) ] = 49 + 10 : 10
8 + 6 × [ 4 + 27 : ( 0 + b × 9 ) ] = 49 + 1
8 + 6 × [ 4 + 27 : ( 0 + b × 9 ) ] = 50
6 × [ 4 + 27 : ( 0 + b × 9 ) ] = 50 - 8
6 × [ 4 + 27 : ( 0 + b × 9 ) ] = 42
[ 4 + 27 : ( 0 + b × 9 ) ] = 42 : 6
[ 4 + 27 : ( 0 + b × 9 ) ] = 7
[ 27 : ( 0 + b × 9 ) ] = 7 - 4
[ 27 : ( 0 + b × 9 ) ] = 3
0 + b × 9 = 27 : 3
0 + b × 9 = 9
b × 9 = 9 - 0
b × 9 = 9
b = 9 : 9
b = 1
