12 - 2 5 = (12 - 2 ) 5 =
12(5 - 2) = 12 5 - 2 =
12 : 2 5 = 12 : ( 2 5 ) =
12 + 52 = 5 : 5 + 2 =
5 + 5 2 - 2 = ( 5 + 5 ) ( 2 - 2 ) =
7- 3 + 4 = 7 - ( 3 + 4 ) =
7 : 7 10 = 7 : ( 7 10) =
17 - 10 - 3 = 17 - 10 + 3 =