(-233) + (-25 + 233) - (-100 + 75)
= -233 + (-25) + 233 + 100 - 75
= -233 -25 + 233 + 100 -75
=(-233+233)-25+100-75
=0-25+100-75
=0
(-233)+(-25+233)-(-100+75)
=(-233)+(-25)+233-(-100)-75
=(-233+233)+(-25-75)-(-100)
=(-100)-(-100)
=(-100)+100
=0
115-(374+115)+(-65+374)
=115-374-115+(-65)+374
=(115-115)+(-374+374)+(-65)
=0+0+(-65)
=(-65)
Bo dau ngoac roi tinh
-25 + ( 38 +26 - 75 ) - ( 38 + 65 -73 )
- ( 28 + 90 + 35 - 76 ) + ( 24 - 83)
Bo dau ngoac roi tinh
(27+65)+(346-27-65)
(42-69+17)-(42+17)
bo dau ngoac roi tinh: a) (27+65)+(346-27-65) ;b)(42-69+17)-(42+17)
bo dau ngoac roi tinh phan a 125-4 .[3-7.(-2)]
Bo dau ngoac roi tinh :
-144 - [29 - (+144) - (-149)]
bo dau ngoac roi tinh
(-7264) + (1543 + 7264)
(435 - 167 - 89) - (435 - 89)
1 : tinh nhanh
a: (-2003)+(-21+75+2003)
b: 1152-(374+1152)+(-65+374)
2: cho X1 + X2 + X3 + ... + X51 = 0 va X1 + X2 + X3 + X4 = X50 + X51 = 1 . tinh X50
Tinh hop lí (neu co the):1125-(374+1125)+(-65+374)
942-2567+2563-1942 17+(-20)+23+(-26)+…+53+(-56)
1152-(374+1152)+(-65+374) -2005+(-21+75+2005)
