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()1 : “+1” “-1” . : . (+1)+(-1)=02 (-1)+(+1)=01 1 + 1 1 0 0 . :3) 1( : 2 3 . (-2)+(-3)4 (-2)+(-3)_= -5 :5 (2) (-3)+2_= -1: 6 (3) 3+(-2)_= 1 :7 (4) (-4)+4_= 0 :8 :(1) (-2)+(-3)=0 1 2-1-2-3-4-5-59 : (2) (-3)+2=0 1 2-1-2-3-4-5-110 (3) 3+(-2)=0 1 2-1-2-331 :11 : (4) (-4)+4=0 1 2-1-2-3-4-5012(1)(-2)+(-3)=-5(2)(-3)+2=-1(3)(+3)+(-2)=1(4)(-4)+4=0 0 .13 . . 0 . 0 . 14 :(1) 180+(-10) (2) (-10)+(-1) (3) 5+(-5) (4) 0+(-2) 15 (+5)+(-2)=-7 ( ) (-5)+(-2)=-3 ( ) (-5)+(+2)=-7 ( ) (+5)+(-2)= 3 ( ) ( ) .16