2155-(174+2155)+(-68+174)
=2155-174-2155-68+174
=(2155-2155)+(-174+174)-68
=-68
-25.21+25.72+49.25
=25.(-21+72+49)
=25.100
=2500
-25.72+25.21-49.25
=25.(-72+21-49)
=25.(-100)
=-2500
2155-(174+2155)+(68+174)=2155-174-2155+68+174=(2155-2155)+(174-174)+68=68
-25.21+25.72+49.25=25(-21+72+49)=25(51+49)=25.100=2500
-25.72+25.21-49.25=-25(72-21+49)=-25.100=-2500
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