Răspuns :
67 - 2 × [ 54 : ( 13 - 21 : 3 ) + 42 : 7 × 3 ] =
67 - 2 × [ 54 : ( 13 - 7 ) + 6 × 3 ] =
67 - 2 × ( 54 : 6 + 6 × 3 ) =
67 - 2 × ( 9 + 18 ) =
67 - 2 × 27 =
67 - 54 =
13
67 - 2 × [ 54 : ( 13 - 7 ) + 6 × 3 ] =
67 - 2 × ( 54 : 6 + 6 × 3 ) =
67 - 2 × ( 9 + 18 ) =
67 - 2 × 27 =
67 - 54 =
13