( 23 + 30 ) - 40 = 53 - 40 = 13
( 47 + 20 ) - 50 = 67 - 50 = 17
( 67 - 50 ) + 30 = 17 + 30 = 47
( 85 - 60 ) + 20 = 25 + 20 = 45
( 23 + 30 ) - 40 = 53 - 40 = 13
( 47 + 20 ) - 50 = 67 - 50 = 17
( 67 - 50 ) + 30 = 17 + 30 = 47
( 85 - 60 ) + 20 = 25 + 20 = 45