a). ( 46 + 24 ) + ( 85 - 77 ) = 70 + 8 = 78
b). ( 17 + 39 ) + ( 25 - 18 ) = 56 + 7 = 63
c). ( 97 - 19 ) - ( 45 - 18 ) = 78 - 27 = 51
d). ( 28 + 68 ) + ( 51 - 50 ) - 10 = 96 + 1 - 10 = 95 - 10 = 85
e). 2× ( 16 + 29 ) - ( 54 + 26 ) = 2 × 45 - 80 = 90 - 80 = 10