Bài 8: Quy tắc dấu ngoặc

tham khảo

1/ -7264 + (1543 + 7264)

= -7264 + 7264 + 1543

= 0 + 1543 = 1543

2/ (144 - 97) - 144

= 144 - 144 - 97

= 0 - 97 = -97

3/ -145 - (18 - 145)

= -145 + 145 - 18

= 0 - 18 = 18

4/ 111 + (-11 + 27)

= 111 - 11 + 27

= 100 + 27 = 127

5/ (27 + 514) - (486 - 73)

= 27 + 514 - 486 + 73

= 27 + 73 + 514 - 486

= 100 + 28

= 28

6/ (36 + 79) + (145 - 79 - 36)

= 36 + 79 + 145 - 79 - 36

= 36 - 36 + 79 - 79 + 145

= 145

7/ 10 - [12 - (-9 - 1)]

= 10 - (12 + 9 + 1)

= 10 - (12 + 10)

= 10 - 10 - 12

= -12

8/ (38 - 29 + 43) - (43 + 38)

= 38 - 29 + 43 - 43 - 38

= 38 - 38 + 43 - 43 - 29

= -29

9/ 271 - [(-43) + 271 -(-17)]

= 271 - (-43 + 271 + 17)

= 271 + 43 - 271 - 17

= 43 - 17 = 26

10/ -144 - [29 - (+144) - (+144)]

= -144 - 29 + 144 + 144

= -29 + 144

= 115

Bài này dễ quá 
Cậu tự làm đi

\(\left(3^{2021}+24.3^{2020}\right):3^{2019}\)

\(=\left(3^{2021}:3^{2019}\right)+\left(24.3^{2020}:3^{2019}\right)\)

\(=3^2+24.3\)

\(=9+72=81\)

(3^2021+24.3^2020):3^2019

=(3^2021:32019)+(24.3^2020:3^2019)

Bỏ ngoặc rồi tính

a) - ( 213 + 74 ) - ( - 2013 - 26 )= -213 -74 + 2013 + 26 =  1752

b) ( 56 + 83 ) - ( 56 - 17 )= 56 + 83 -56+ 17 = 100

c) - ( 92 - 18 ) + ( 92 - 118 )= -92 + 18 + 92 -118 = -100

a)=-213-74-213+26

=-474

a) - ( 213 + 74 ) - ( - 2013 - 26 )

= - 213 - 74 + 2013 + 26

= ( - 213 + 2013 ) + ( - 74 + 26 )

= 1800 - 48

= 1752

b) ( 56 + 83 ) - ( 56 - 17 )

= 56 + 83 - 56 + 17

= ( 56 - 56 ) + ( 83 + 17 )

= 0 + 100

= 100

c) - ( 92 - 18 ) + ( 92 - 118 )

= - 92 + 18 + 92 - 118

= ( - 92 + 92 ) + ( 18 - 118 )

= 0 - 100

= - 100

\(d.\left(-524\right)-\left[\left(476+245\right)-45\right]\\ =-524-476-245+45\\ =\left(-524-476\right)-\left(245-45\right)\\ =-1000-200\\ =-1200\)

\(a.\left(67-5759\right)+5759\\ =67-5759+5759\\ =67+\left(5759-5759\right)\\ =67+0\\ =67\)

\(b.\left(-3023\right)-\left(765-3023\right)\\ =-3023-765+3023\\ =\left(-3023+3023\right)-765\\ =0-765\\ =-765\)

\(c.631+\left[587-\left(287+231\right)\right]\\ =631+587-287-231\\ =\left(631-231\right)+\left(587-287\right)\\ =400+300\\ =700\)

a.67                                                                      b.-765

c.700                                                                    d.-1200

Bài 3.21:

b: =28+19-28-32+57

=76-32

=44

=-350-70

=-420

-420

214-(-36)+(-305)

A x=10

B x =2

C x=-7

D x=20

A x=-4

B x =2

C x=-7

D x=20

giải chi tiết giúp mình

b: =-24+76=52

a) \(\left(-28\right)+\left(-35\right)-92+\left(-82\right)\)

\(=-28-35-92-82\)

\(=-237\)

b) \(15-\left(-38\right)+\left(-55\right)-47\)

\(=15+38-55-47\)

\(=-49\)

a) \(31+32+33+34+35-11-12-13-14-15\)

\(=\left(31-11\right)+\left(32-12\right)+\left(33-13\right)+\left(34-14\right)+\left(35-15\right)\)

\(=20+20+20+20+20\)

\(=20.5\)

\(=100\)

a: =-389-25=-414