\(\left(27+55\right)+\left(345-27-55\right)\)

\(=27+55+345-27-55\)

\(=\left(27-27\right)+\left(55-55\right)+345\)

\(=0+0+345\)

\(=345\)

\(38.65+38.50-38.15\)

\(=38.\left(65+50-15\right)\)

\(=38.100\)

\(=3800\)

\(\left(123-60\right)-\left(2017-60+123\right)\)

\(=123-60-2017+60-123\)

\(=\left(123-123\right)-\left(60-60\right)-2017\)

\(=0-0-2017\)

\(=-2017\)

Bỏ dấu ngoặc rồi tính:

(27 + 55 ) + ( 345 - 27 - 55 )

= 27 + 55 + 345 - 27 - 55

= (27-27) + (55-55) + 345

= 0 + 0 + 345

= 345

Tính nhanh:

38.65 + 38.50 - 38.15

= 38.(65+50-15)

= 38.100

= 3800

Bỏ ngoặc rồi tính:

( 123 - 60 ) - ( 2017 - 60 + 123 )

= 123 - 60 - 2017 + 60 - 123

= (123-123) + (60-60) - 2017

= 0 + 0 - 2017

= 0 - 2017

= -2017

38.65+38.50-38.15

=38.(65+50-15)

=38.100

=3800

a)(167+35)+(134-167-35)    b)(43-31+57)-(243-345+54)      c)(89-76)+(76-89+28)     d)(243+46-345)-(243-345+54)

=167+35+134-167-35          =43-31+51-43+345-54           =89-76+76-89+28          =243+46-345-243+345-54

=167-167+35-35+134          =12+51-43+345-54               =0+28                           =289-345-243+345-54

=0+0+134                          =63-43+291                         =28                               =(-56)-243+345-54

=134                                 =20+291=311                                                            =(-299)+345-54

                                                                                                                        =46-54=-8

(-257)-[(-257+156)-56]

=(-257)-(-257+156-56)

=(-257)-(-257+100)

=-257+257-100

=(-257+257)-100

=0-100

=-100

-100 do

 (-257)-[(-257+156)-56]

=(-257)+257+156-56

=[(-257)+257]+(156-56)

=0+100

=100

k cho mk nha b

Lời giải:
a. $=13-47-13-59+81+35-13$

$=(13-13-13)-(47+59)+(81+35)$
$=-13-106+116=-13+(116-106)=-13+10=-3$

b.

$=345-61+84+61-116-345$

$=(345-345)+(-61+61)-(116-84)$

$=0+0-32=-32$

a, $(13-47)-(13+59-81)+(35-13)$

$=13-47-13-59+81+35-13$

$=(13-13)+(-47-13)+(-59+81)+35$

$=-60+22+35$

$=-38+35$

$=-3$

$---$

b, $(345-61+84)-(-61+116+345)$

$=345-61+84+61-116-345$

$=(345-345)+(-61+61)+(84-116)$

$=-32$

Bài 1:

1: =15+37+52-37-17=52-2=50

2: =38-42+14-25+27+15=62-42+29=20+29=49

Bài 1: Bỏ ngoặc rồi tính

3) (21-32) - (-12+32)=21-32-(-12)-32=21-32+12-32=-31

4) (12+21) - (23-21+10)=12+21-23+21-10=21

5) (57-725) - (605-53)=57-725-605+53=-1220

6) (55+45+15) - (15-55+45)=55+45+15-15+55-45=55+55=110

Bài 2: Tính các tổng sau một cách hợp lí

1) (-37) + 14 + 26 + 37=(-37+37)+(14+26)=0+40=40

2) (-24) +6 + 10 + 24=(-24+24)+(6+10)=0+16=16

3) 15 + 23 + (-25) + (-23)=(15-25)+(23-23)=-10+0=-10

4) 60 + 33 + (-50) + (-33)=(60-50)+(33-33)=10+0=10

5) (-16) + (-209) + (-14) + 209=(-16-14)+(-209+209)=-30+0=-30

6) (-12) + (-13) + 36 + (-11)=(-11-12-13)+36=-36+36=0

=15+37+52-37-17 =(37-37)+52+15-17 =0+52+15-17 =67-17 =50

(38 – 42 + 14) – (25 – 27 – 15) =38-42+14-25+27+15 =27 c. -(21 – 32) – (-12 + 32) =-21+32+12-32 =-9 d. -(12 + 21 – 23) - (23 – 21 + 10) =-12-21+23-23+21-10 =-22 e. (57 – 725) – (605 – 53) =57-725-605+53 =-1220 f. (55 + 45 + 15) – (15 – 55 + 45) =55+45+15-15+55-45 =110

-55+80-91-2012-80+91

=91-91+80-80-2012-55

=-2067

-55+80-11-2012-80+91

= -1987

-55+80-91-2012-80+91

=91-91+80-80-2012-55

=-2067

57-725-605+53=-1220

55+45+15-15+55-45=110

Ủng hộ mk nhaaa

Câu 1:

= 57 - 725 - 605 - 53

=  ( 725 - 605 ) - ( 57 - 53 )

= 120 - 4

= 116

Câu 2 làm tương tự

sơ ry mk mới học lớp 5

17-(35+22-44)+(55-56)

=17-35-22+44+55-56

=(-18)-22+44+55-56

=(-40)+44+55-56

=4+55-56

=59-56

=3

17-(35+22-44)+(55-56)

=17-35-22+44+55-66

=-7

A = 17- (35+22-44) + (55-56)

    = 17- 35 -22 +44 +55 - 56 

    = 3