A, 35 x 18 - 5 x 7 x 28.

   = 35 x 18 - 35 x 28.

   = 35 x ( 18 - 28 )

  = 35 x ( - 10 )

  = -350.

B, 45 - 5 x ( 12 + 9 ).

  = 45 - 5 x 12 + 5 x 9

 = 45 - 60 + 45

 = ( 45 + 45 ) - 60

 = 90 - 60

= 30.

#Học tốt.

A, 35×18-5×7×28 = 35x18-5x7x28

                             = 35x18-35x28

                             = 35(18-28)

                             = 35.(-10)

                             = -350

B, 45-5× (12+9) = 45-5x12-5x9

                          = 45-60-45

                          =(45-45)-60

                          = 0-60

                           =-60

                           = -350

A, 35×18-5×7×28 = 35x18-5x7x28

                             = 35x18-35x28

                             = 35(18-28)

                             = 35.(-10)

                             = -350

B, 45-5× (12+9) = 45-5x12-5x9

                          = 45-60-45

                          =(45-45)-60

                          = 0-60

                           =-60

45 - 5 . ( 12 + 9 )

= 45 - 5 . 21

= 45 - 105

= -60 

45-5.(12+9)

=45-5.21

=45-105

=-60

45 - 5 . (12+9)

= 45 - 5.21

= 5.9 -5.21

= 5 . ( 9-21)

= 5 . (-12)

= -60 

k mk nha

45 - 5 . (12 + 9)

= 45 - 5 . 21

= 45 - 105

= -60

-48 + 48 . (-78) + 48 . (-21)

= -48 + (-48) . 78 + (-48) . 21

= -48 . (78 + 21 + 1)

= -48 . 100

= -4800

45 - 5 . (12 + 9)

= 45 - 5.21

=9 . 5 + 5 .21

= (9 + 21).5

= 30.5

= 150

-48 + 48 .(-78) + 48.(-21)

= 48.(-1 -78 - 21)

= 48.(-100) 

= -4800

k mik nha bn

45-5.(12+9)

=45-5.9+5.12

=45-45+60

=0+60=60

-48+48.(-78)+48.(-21)

= -48+(-48).78+(-48).21

= -48.(78+21+1)

= -48 . 100

= -4800

45-5x(12+9)

45-5x9+5x12

45-45-60

0-60

=-60

tk nha

45-5 x (12+9)

=45-5x21

=45-105

=-60

Bạn có thể tính nhanh ko

35.18-5.7.28=35.18-35.28=35(18-28)=-350

45-5.12-5.9=45-60-45=-60

=24.16-24.5-16.24-16.5=5(-24-16)=5.-40=-200

 35 . 18 - 5 . 7 . 28 = 35 . 18 - 35 . 28

= 35 . (18 - 28)

= 35 . (-10)

= -350

45 - 5 . (12 + 9) = 45 - 5 . 9 + 5 . 12

= 45 - 45 + 60

= 60

24 . (16 - 5) - 16 . (24 - 5) = 24 . 16 - 24 . 5 - 16 . 24 + 16 . 5

= (24 . 16 - 16 . 24) + (16 . 5 - 24 . 5)

=0 + 5 . (16 - 24)

= 5. (-8)

= -40

12 mũ 5 nhân 9 mũ 6 phần 27 mũ 5 nhân 2 mũ 12

Thực hiện phép tính ( bằng cách hợp lí nếu có thể ) 

A. 2/3 - (- 1/4)+3/5-(+7/45)-(-5/9)+1/12+1/39 

B. 6.(-2/3)^2 - 3(-2/3)^2 - 2 : (-3/2)+4

a: \(5\cdot11\cdot18+9\cdot31\cdot10+4\cdot29\cdot45\)

\(=11\cdot\left(5\cdot18\right)+31\cdot\left(9\cdot10\right)+29\cdot2\cdot\left(2\cdot45\right)\)

\(=90\left(11+31+29\cdot2\right)\)

\(=90\cdot100=9000\)

b: \(37\cdot39+78\cdot14+13\cdot85+52\cdot55\)

\(=37\cdot39+39\cdot2\cdot14+13\cdot85+13\cdot4\cdot55\)

\(=39\left(37+2\cdot14\right)+13\cdot\left(85+4\cdot55\right)\)

\(=39\cdot65+13\cdot305\)

\(=13\left(65\cdot3+305\right)=13\cdot500=6500\)

a)

5.11.18+9.31.10+4.29.455.11.18+9.31.10+4.29.45

=90.11+90.31+2.29.90=90.11+90.31+2.29.90

=90.(11+31+2.29)=90.(11+31+2.29)

=90.100=9000

b)

37.39+78.14+13.85+52.5537.39+78.14+13.85+52.55

=37.39+39.2.14+13.5.17+13.4.5.11=37.39+39.2.14+13.5.17+13.4.5.11

=39.(37+2.14)+65.17+65.44=39.(37+2.14)+65.17+65.44

=39.65+65.(17+44)=39.65+65.(17+44)

=39.65+65.61=39.65+65.61

=65.(39+61)=65.(39+61)

=65.100=6500

a)

5.11.18+9.31.10+4.29.45

=90.11+90.31+2.29.90

=90.(11+31+2.29)

=90.100

=9000

b)

37.39+78.14+13.85+52.55

=37.39+39.2.14+13.5.17+13.4.5.11

=39.(37+2.14)+65.17+65.44

=39.65+65.(17+44)

=39.65+65.61

=65.(39+61)

=65.100

=6500