Bài 1: Thực hiện các phép tính sau
1, 12-(13+7)+(-9)
2,47-(90-13+47)-13
3,-(145-79)+(245-79)
4,-13-|-34|-7+98
5,|-87|+(-17)-(14-80)
6, (-17-30)+28-(-5)
7, 12-(-7+40)+37
8, (23-45+87)-(97+23)
9,13-(-67)+35-6
10, (-76+23)-(-45+33)
11, (160-200)-(560-|-235+35|)
12, 45:|-6-3|+(-15)-(-7)-34
13, -56-(-45)+13-45-(-56)
1, 12-(13+7)+(-9)
=12-20+(-9)
=8+(-9)
=-1
2, 47-(90-13+47)-13
=47-90+13-47-13
=(47-47)-90+(13-13)
=0-90+0
=-90
3, -(145-79)+(245-79)
=-145+79+245-79
=(-145+245)+(79-79)
=100+0
=100
4, -13-l-34l-7+98
=-13-34-7+98
=-47-7+98
=-54+98
=44
5, l-87l+(-17)-(14-80)
=87-17-66
=70-66
=4
6, (-17-30)+38-(-5)
=-47+38+5
=-9+5
=-4
7, 12-(-7+40)+37
=12-33+37
=-21+37
=16
8, (23-45+87)-(97+23)
=65-120
=-55
9, 13-(-67)+35-6
=13+67+35-6
=80+35-6
=115-6
=109
10, (-76+23)-(-45+33)
=-53-(-12)
=-53+12
=-41
11, (160-200)-(560-l-235+35l)
=-40-(560-200)
=-40-360
=-400
12, 45:|-6-3|+(-15)-(-7)-34
=45÷9-15+7-34
=5-15+7-34
=-10+7-34
=-3-34
=-37
13, -56-(-45)+13-45-(-56)
=-56+45+13-45+56
=(-56+56)+13+(45-45)
=0+13+0
=13
Đáp án:
1,=12-13-7-9=-17
2,=47-90+13-47-13-90
3,=-145+79+245-79=100
4,=-13-34-7+98=44
5,=87-17-14+80=136
6,=-17-30+28+5=-14
7,=12+7-40+37=16
8,=23-45+87-97-23=-55
9,=13+67+35-6=109
10,=-76+23+45-33=-41
11,=(160-200)-(500-200)
=160-200-500+200
=-340
12,=45÷9-15+7-34
=5-15+7-34=37
13,=-56+45+13-45+56=13