a,39-63+47-(+21)-(-15) b, -(+32)+(+17)-(-23)-(+46) c, 18-82+42-(+113)+(+55)
=-27+47-21+15 = -32+17+23-26 = -64+42-113+55
=20-21+15 = -15+23-26 = -22-113+55
=-1+15 = 8-26 = -135+55
=14 = -18 = 80
d,+(-96)-(-119)+54-(+25) e,-(-82)+13-46+(-57)-(+90) f,+(+94)-(+63)-(-75)+(-124)
=-96+119+54-25 = 82 +13-46-57-90 =94-63+75-124
=23+54-25 =95-46-57-90 =31+75-124
=77-25 =49-57-90 =106-124
=52 =8-90 =18
=98