Bài 1

a) (3x - 2⁴).7³ = 2.7⁴

3x - 16 = 2.7⁴ : 7³

3x - 16 = 2.7

3x - 16 = 14

3x = 14 + 16

3x =30

x = 30 : 3

x = 10

b) x - [42 + (-28)] = -8

x - 14 = -8

x = -8 + 14

x = 6

c) 4 - 7.x = x - (13 - 4)

x + 7x = 4 + 9

8x = 13

x = 13/8

Bài 1: a,   (3\(x\) - 2⁴ ).7³ = 2.7⁴

                3\(x\) - 2⁴    = 2.7⁴ : 7³

                3\(x\)  - 16   = 14

                 3\(x\)           = 30 

                    \(x\)          = 10

b, \(x\) - (42 + (-28) ] = -8

    \(x\) - 14 = -8

    \(x\)        = 14 - 8

    \(x\)        = 6

c, 4 - (7\(x\)) = \(x\) - (13 - 4)

   4 - 7\(x\)   = \(x\) - 9

        \(x\) + 7\(x\) = 4 + 9

          8\(x\)     = 13

             \(x\)    = \(\dfrac{13}{8}\)

Bài 2

a) 58.75 + 58.50 - 58.25

= 58.(75 + 50 - 25)

= 58.100

= 5800

b) 27.39 + 27.63 - 2.27

= 27.(39 + 63 - 2)

= 27.100

= 2700

c) 48.13 + 48.115 + 134.52

= 48.(13 + 115) + 134.52

= 48.128 + 134.52

= 6144 + 6968

= 13112

d) 27.121 - 87.27 + 73.34

= 27.(121 - 87) + 73.34

= 27.34 + 73.34

= 34.(27 + 73)

= 27.100

= 2700

  Bằng 230.825 nha bạn!

  Chúc bạn học giỏi!

mà bn ơi đáu chấm đó là nhân hay là phẩy

48 x 19 + 48 x 115 + 134 x 52

= 48 x (19 + 115) + 134 x 52

= 48 x 134 + 134 x 52

= 134 x (48 + 52)

= 134 x 100

= 13400

27 x 121 - 87 x 27 + 73 x 34

= 27 x (121 - 87) + 73 x 34

= 27 x 34 + 73 x 34

= 34 x (27 + 73)

= 34 x 100

= 3400

125 x 98 - 125 x 46 - 52 x 23

= 125 x (98 - 46) - 52 x 23

= 125 x 52 - 52 x 23

= 52 x (125 - 23)

= 52 x 102

= 5304

136 x 23 + 136 x 17 + 40 x 36

= 136 x (23 + 17) + 40 x 36

= 136 x 40 + 40 x 36

= 40 x (136 + 36)

= 40 x 172

= 6880

17 x 93 + 116 x 83 + 17 x 23

= 17 x (93 + 23) + 116 x 83

= 17 x 116 + 116 x 23

= 116 x (17 + 23)

= 116 x 40

= 4640

19 x 27 + 47 x 81 + 19 x 20

= 19 x (27 + 20) + 47 x 81

= 19 x 47 + 47 x 81

= 47 x (19 + 81)

= 47 x 100

= 4700

87 x 23 + 13 x 93 + 70 x 87

= 87 x (23 + 70) + 13 x 93

= 87 x 93 + 13 x 93

= 93 x (87 + 13)

= 93 x 100

= 9300

Học tốt!!!

1) Tính nhanh

a) Ta có: \(5\cdot79\cdot4\cdot2\cdot25\)

\(=\left(5\cdot2\right)\cdot\left(4\cdot25\right)\cdot79\)

\(=79\cdot10\cdot100\)

\(=79000\)

b) Ta có: \(27\cdot121-87\cdot27+73\cdot34\)

\(=27\cdot\left(121-87\right)+73\cdot34\)

\(=27\cdot34+73\cdot34\)

\(=34\cdot\left(27+73\right)\)

\(=34\cdot100=3400\)

\(A=8\cdot17\cdot125=\left(125\cdot8\right)\cdot17=1000\cdot17=17000\)

\(B=\left(25\cdot4\right)\cdot37=100\cdot37=3700\)

\(C=\left(75+50-25\right)\cdot58=100\cdot58=5800\)

\(D=\left(39+63-2\right)\cdot27=100\cdot27=2700\)

A=8.17.125= (8.125).17= 1000.17=17000

b=4.37.25=(4.25).37=100.37=3700

c= 58.75+58.50-58.25= 58.(75+50 - 25)= 58.100=5800

d=27.39+27.63-2.27= 27.(39+63-2)=27.100=2700

58.75-58.50-58.25=58(75-50-25)=58.0=0

58.75 - 58.50 - 58.25=58.(75-50-25)=58.0=0

a,48.(19+115)+134.52=48.134+134.52=134.(48+52)=134.100=13400

b,27.(121-87)+73.364=27.34+73.34=34.(73+27)=34.100=3400

c,125.(98-46)-52.25=125.52-52.25=25.(125-25)=25.100=2500

tick nha

58.75+58.50-58.25

=58.(75+50-25)

=58.100

=5800

Tích mình nhé!

20:2^2 -5^9:5^8

58.75+58.50-58.5

=58.(75+50-5)

=58.120

=6960

_Hok tốt_

\(=58.\left(75+50-5\right)\)

\(=58.120\)

\(=6960\)

58.75+58.50-58.5

=58.(75+50-5)

=58.120

=6960

Hok_Tốt