a) `123 - 27 + 27 + 13 - 123`

`= (123 - 123) + (27 - 27) + 13`

`= 0 + 0 + 13`

`= 13`

`---`

b) `175 + 25 + 13 + 15 - 175 - 25`

`= (175-175)+(25-25)+25+13`

`=0+0+25+13`

`=28`

`---`

c) \(53\times39+47\times39+53\times21+47\times21\)

\(=\text{[}\left(53+47\right)\times39]+\left[\left(53+47\right)\times21\right]\)

\(=\left(100\times39\right)+\left(100\times21\right)\)

\(=3900+2100\)

`=6000`

`---`

d) \(49\times35+49\times16-49\times61\)

`=` \(49\times\left(35+16-61\right)\)

`=` \(49\times\left(-10\right)\)

`=-490`

    -5 + (-37 - 45 + 51) - (-37 + 51)

=  -5  - 37 - 45 + 51 + 37 - 51

=  - (5 + 45) - (37 - 37) + (51 - 51)

= - 50 - 0 + 0

= - 50

  - (15 - 47 + 58) + (15 - 47 ) + 3

= - 15 + 47 - 58 + 15 - 47 + 3

= (-15 + 15) + (47 - 47) - (58 - 3)

= 0 + 0 - 55

= - 55

  (53 - 45 - 49) - (53 + 45 - 49)

= 53 -  45 - 49 - 53 - 45 + 49

= (53 - 53) + (-49 + 49) - (45 + 45)

= 0 + 0 - 90

= - 90 

    13 - 15 + 49 - 13 + 15 - 48

=  (13 - 13) + (-15 + 15) + (49 - 48)

= 0 + 0 + 1

=  1 

15+13 -15-13 +49-48

1, 42 x 53 + 47 x 156 - 47 x 114

= 42 x 53 + 47 x ( 156 - 114 ) 

= 42 x 53 + 47 x 42

= 42 x ( 53 + 47 ) 

= 42 x 100

= 4200

2, 53 x ( 51 + 4 ) + 53 x ( 49 + 96 ) + 53 

= 53 x 51 + 53 x 4 + 53 x 49 + 53 x 96

= 53 x ( 51 + 49 ) + 53 x ( 96 + 4 ) + 53

= 53 x 100 + 53 x 100 + 53

= 5300 + 5300 + 53

= 10653

3, 42 x ( 15 + 96 ) + 6 x ( 25 + 4 ) x 7 

= 42 x 15 + 42 x 96 + 42 x 25 + 42 x 4 

= 42 x ( 15 + 25 ) + 42 x ( 96 + 4 )
= 42 x 40 + 42 x 100

= 42 x ( 100 + 40 )

= 42 x 140 

= 5880

Tk mk nha !! ~

42. 53 + 47. 156 - 47. 114 = 42.53 +47.(156-114)
                                          =42.53 +47. 42
                                          = 42(53+47)
                                          = 42.100     = 4200

53. ( 51 + 4 ) + 53. ( 49 + 96 ) + 53 = 53(51+4+49+96+1)

                                                        = 53. 201        = 10653

42. ( 15 + 96 ) + 6. ( 25 +4 ). 7 = 42. ( 15 + 96 ) + 42(25+4)

                                                  = 42(15+96+25+4)

                                                  = 42. 140         = 5880

 mk lm xong rồi add friend nha

TRẢ LỜI:

A/ 42 . 53 + 47 . 156 - 47 . 114

=2226 + 7332 - 5358

=9558 - 5358

=4200

B/ 53 . (51 + 4) + 53 .(49 + 96) + 53

=53 . 51 + 53 . 4+ 53. 49+ 53. 96+ 53

=2703 + 212 +2597 +5088 + 53

=2924 + 7738

=10662

C/ 42.(15+96)+6.(25+4).7

=42. 15+42. 96+6 . 25+6.4.7

=630+4032+150+168

=4980

CHÚC BN HOK TỐT

Ta có: \(13\cdot\left(-47\right)-53\cdot13\)

\(=13\cdot\left(-47-53\right)\)

\(=13\cdot\left(-100\right)=-1300\)

Ta có: \(27\cdot\left(-67\right)+33\cdot\left(-27\right)\)

\(=27\cdot\left(-67\right)-33\cdot27\)

\(=27\left(-67-33\right)\)

\(=27\cdot\left(-100\right)=-2700\)

Ta có: \(-49\cdot65+36\cdot\left(-49\right)+49\)

\(=-49\cdot65+\left(-49\right)\cdot36+\left(-49\right)\cdot\left(-1\right)\)

\(=-49\cdot\left(65+36-1\right)\)

\(=-49\cdot100=-4900\)

Ta có: \(136\cdot\left(-47\right)+36\cdot47\)

\(=\left(-136\right)\cdot47+36\cdot47\)

\(=47\cdot\left(-136+36\right)\)

\(=47\cdot\left(-100\right)=-4700\)

Ta có: \(\left(-48\right)\cdot72+36\cdot\left(-304\right)\)

\(=-96\cdot36+36\cdot\left(-304\right)\)

\(=36\cdot\left(-96-304\right)\)

\(=36\cdot\left(-400\right)=-14400\)

Đáp án cần chọn là: D

chịu

gg

135*57+135*86-35*143= 135 (57+86)-35*143=135*143-35*143=143 (135-35)=143*100=14300

91*47+49*53-18*47+24*53=(91*47-18*47)+(49*53+24*53)=47*(91-18)+53*(49+24)=47*73+53*73=73*(47+53)=73*100=7300

a, 

\(135\cdot57+135\cdot86-35\cdot143\)  

\(=135\cdot\left(57+86\right)-35\cdot143\)  

\(=135\cdot143-35\cdot143\) 

\(=143\cdot\left(135-35\right)\) 

\(=135\cdot100\) 

\(=13500\) 

b, 

\(91\cdot47+49\cdot53-18\cdot47+24\cdot53\) 

\(=91\cdot47-18\cdot47+49\cdot53+24\cdot53\) 

\(=47\cdot\left(91-18\right)+53\cdot\left(49+24\right)\) 

\(=47\cdot73+53\cdot73\) 

\(=73\cdot\left(47+53\right)\) 

\(=73\cdot100\) 

\(=7300\)   

45-58+(-45)+(+58)-3=45-58-45+58-3=(45-45)+(58-58)-3=-3

(-57)-(-12)+3-(-57)=-57+12+3+57=(-57+57)+12+3=15

-(-24)-(-30)+(-24)-30+8=24+30-24-30+8=(24-24)+(30-30)+8=8

-(-12)+(+19)-(+12)+8-19=12+19-12+8-19=(12-12)+(19-19)+8=8

47-(-53)+(-47)-(+53)=47+53-47-53=(47-47)+(53-53)=0

-(+28)+32-(-28)+(-34)=-28+32+28-34=(-28+28)-(34-32)=-2

15-(+72)+(-15)+(+72)=15-72-15+72=(15-15)+(72-72)=0

20-(+46)+(-25)-(-46)=20-46-25+46=(20-25)+(46-46)=-5

28-(-32)+(-28)-32+5=28+32-28-32+5=(28-28)+(32-32)+5=5

-75+(-49)+(+75)+49-12=-75-49+75+49-12=(-75+75)+(49-49)-12=-12

\(...=45-58-45+58-3=-3\)

\(...=-57+12+3+57=15\)

\(...=24+30-24-30+8=8\)

\(...=12+19-12+8-19=8\)

\(...=47+53-47-53=0\)

\(...=-28+32+28-34=-2\)

\(...=15-72-15+72=0\)

\(...=20-46-25+46=-5\)

\(=...28+32-28-32+5=5\)

\(...=-75-49+75+49-12=-12\)

53 x 39 + 49 x 39 - 53 x 21 - 47 x 21

= 39 x ( 53 + 49 ) - 21 x ( 53 - 47 )

= 39 x 102 - 21 x 6

= 3978 - 136

= 3842

53 x 39 + 49 x 39 - 53 x 21 - 47 x 21

= 39 x ( 53 + 49 ) - 21 x ( 53 - 47 )

= 39 x 102 - 21 x 6

= 3978 - 136

= 3842

bàng 3842

3) 124 + (-52) . 124 + (-124 ) . (-47)
= 124 + (-52) . 124 + 124 . 47
= 124 \(\left[\left(-52\right)+1+47\right]\)
= 124.(-3)
= -372

4) 53. (51 + 4) + 53. ( 49+96) + 53
= 53 . 55 + 53 . 145 + 53
= 53(55+145) + 53
= 53 . 200 + 53
= 10600 +53
= 10653