Bài 4:
a: (2354-45)-2354
=2354-45-2354
=-45
b: (-2009)-(234-2009)
=-2009-234+2009
=-234
c: (16+23)+(153-16-23)
=16+23+153-16-23
=153
d: (134-167+45)-(134+45)
=134-167+45-134-45
=-167
e: -3752-(29-3632)-51
=-3752-29+3632-51
=(3632-3752)+(-51-29)
=-120-80
=-200
f: 321+{-15+[30+(-321)]}
=321+{-15+30-321}
=321+15-321
=15
g: 4524-(864-999)-(36+3999)
=4524-864+999-36-3999
=4524-(864+36)+(999-3999)
=4524-900-3000
=4524-3900
=624
h: 1000-(137+572)-(263-172)
=1000-137-572-263+172
=1000-(137+263)-(572-172)
=1000-400-400
=200
i: -(-1456+23)-1456+153
=1456-23-1456+153
=153-23
=130
k: (-1999)-(-234-1999)
=-1999+234+1999
=234
l: (116+124)-(215-116-124)
=116+124-215+116+124
=240+240-215
=240+25
=265
m: (435-167-89)-(435-89)
=435-167-89-435+89
=-167
n: (1267-196)-(267+304)
=1267-196-267-304
=(1267-267)-(196+304)
=1000-500
=500
o: (2002-79+15)-(-79+15)
=2002-79+15+79-15
=2002
p: (3965-2378)-(437-1378)-528
=3965-2378-437+1378-528
=(3965-437-528)-(2378-1378)
=3000-1000
=2000
q: -329-(15+101)-(25-440)
=-329-15-101-25+440
=-15-25
=-40
