a) 70 - 5 .(x -3 ) =45

            5 . ( x - 3 ) = 70 - 45

             5 . ( x - 3 ) = 25

                    x - 3    =  25 : 5 

                     x - 3 = 5 

                     x      = 5 + 3

                     x       = 8

b) 156 - ( x + 61 )+82

    sai đề ( không có kết quả )

c) 10 +2 .x = 4⁵ : 4³

    10 + 2 . x = 4² = 16

             2 . x = 16 -10

             2 . x = 6

                  x = 6 : 2

                  x = 3

d) [(10 - x ).2 +3 ];3 -2=13

     [ ( 10 - x ) . 2 + 3 ] : 3 = 13 + 2

     [ ( 10 - x  ) . 2 + 3 ] : 3 = 15 

      [ ( 10 - x  ) . 2 + 3 ]    = 15 x 3

       [ ( 10 - x  ) . 2 + 3 ]    = 45

         ( 10 - x  ) . 2             = 45 - 3

         ( 10 - x  ) . 2             = 42

           10 - x                      = 42 : 2 

           10 - x                      = 21

                  x                       = 10 - 21

                  x                       = - 11

hok tốt

\(70-5\left(x-3\right)=45\)

\(5\left(x-3\right)=70-45\)

\(5\left(x-3\right)=25\)

\(x-3=\frac{25}{5}=5\)

\(x=5+3\)

\(x=8\)

\(10+2x=\frac{4^5}{4^3}\)

\(10+2x=4^2=16\)

\(2x=16-10\)

\(2x=6\)

\(x=\frac{6}{2}=3\)

a) 45 x 76 + 90 x 12

= 45 x 76 + 45 x 2 x 12

= 45 x 76 + 45 x 24

= 45 x ( 76 + 24 ) 

= 45 x 100

= 4500

b) 2 x 31 x 12 + 4 x 6 x 69

= 24 x 31 + 24 x 69

= 24 x ( 31 + 69 )

= 24 x 100

= 2400

c) 36 x 28 + 36 x 82 + 64 x 69 + 64 x41

= 36 x ( 28 + 82 ) + 64 x ( 69 + 41 )

= 36 x 110 + 64 x 110

= 110 x ( 36 + 64 )

= 110 x 100

= 11 000

d) 156 ( x + 61)  = 82

=> x + 61 = \(\frac{82}{156}\)

=> x + 61 = \(\frac{41}{78}\)

=> x = \(\frac{41}{78}\)- 61

=> x = \(\frac{-4717}{78}\)

45 x 76 + 90 x 12 = 45 x 76 + 45 x 2 x 12

= 45 x 76 + 45 x 24

= 45 x (76 + 24)

= 45 x 100 

= 4500

b) 2 x 31 x 12 + 4 x  6 x 69 = 62 x 12 + 2 x 12 x 69

= 62 x 12 + 138 x 12

= (62 + 138) x 12

= 200 x 12 = 2400

a, 45 x 76 + 90 x 12

= ( 45 x 12 ) + ( 76 x 90 )

=  540     +   6840

=     7 380

c,

= 36 x ( 28 + 82 ) +  64 x ( 69 + 41 )

= 36 x  110    +   64 x 110

= 110 x ( 36 + 64 )

= 110 x 100

= 11000

\(a,14-5+x=30\)

\(\Rightarrow9+x=30\Rightarrow x=30-9\)

\(\Rightarrow x=21\)

\(b,45-\left(3+x\right)=14\)

\(\Rightarrow3+x=45-14\)

\(\Rightarrow3+x=31\Rightarrow x=31-3\)

\(\Rightarrow x=28\)

\(c,18+\left(-3+x\right)-\left(44-x\right)=55\)

\(\Rightarrow18-3+x-44+x=55\)

\(\Rightarrow2x-29=55\Rightarrow2x=55+29\)

\(\Rightarrow2x=84\Rightarrow x=84:2\)

\(\Rightarrow x=42\)

\(d,\left(x-45\right).27=0\)

\(\Rightarrow x-45=0\Rightarrow x=45\)

\(a,14-5+x=30\)

\(\Rightarrow9+x=30\)

\(\Rightarrow x=30-9=21\)

\(b,45-\left(3+x\right)=14\)

\(\Rightarrow3+x=45-14=31\)

\(\Rightarrow x=31-3=28\)

a) 124 + (118 - x) = 217

118 - x = 217 - 124

118 - x = 93

x = 118 - 93

x = 25

b) 156 - (x + 61) = 82

x + 61 = 156 - 82

x + 61 = 74

x = 74 - 61

x = 13

c) 219 - 7(x + 1) = 100

7(x + 1) = 219 - 100

7(x + 1) = 119

x + 1 = 119 : 7

x + 1 = 17

x = 17 - 1

x = 16

d) (3x - 6).3 = 3⁴

3x - 6 = 3⁴ : 3

3x - 6 = 3³

3x - 6 = 27

3x = 27 + 6

3x = 33

x = 33 : 3

x = 11

e) 231 - (x - 6) = 1339 : 13

231 - (x - 6) = 103

x - 6 = 231 - 103

x - 6 = 128

x = 128 + 6

x = 134

a) 124 + (118 - x) = 217

118 - x = 217 - 124

118 - x = 93

x = 118 - 93

x = 25

b) 156 - (x + 61) = 82

x + 61 = 156 - 82

x + 61 = 74

x = 74 - 61

x = 13

c) 219 - 7(x + 1) = 100

7(x + 1) = 219 - 100

7(x + 1) = 119

x + 1 = 119 : 7

x + 1 = 17

x = 17 - 1

x = 16

d) (3x - 6) . 3 = 3⁴

(3x - 6) . 3 = 81

(3x - 6) = 81 : 3

(3x - 6) = 27

3x = 27 + 6

3x = 33

x = 33 : 3 

x = 11

e) 231 - (x - 6) = 1339 : 13

231 - (x - 6) = 103

(x - 6) = 231 - 103

x - 6 = 128

x = 128 + 6

x = 134

cô cấm dùng máy tính -) 

lớp 9 ms đc dùng:_)

a, \(231-\left(x-6\right)=1339:13\)

\(\Leftrightarrow231-\left(x-6\right)=103\)

\(\Leftrightarrow x-6=128\)

\(\Leftrightarrow x=134\)

Vậy .....

b, \(70-5\left(2x-3\right)=45\)

\(\Leftrightarrow5\left(2x-3\right)=25\)

\(\Leftrightarrow2x-3=5\)

\(\Leftrightarrow2x=8\)

\(\Leftrightarrow x=4\)

Vậy ....

c, \(156-\left(x+61\right)=82\)

\(\Leftrightarrow x+61=74\)

\(\Leftrightarrow x=13\)

Vậy ....

d, \(6\left(5x+35\right)=330\)

\(\Leftrightarrow5x+35=55\)

\(\Leftrightarrow5x=20\)

\(\Leftrightarrow x=4\)

Vậy ......

e, \(936-\left(4x+24\right)=72\)

\(\Leftrightarrow4x+24=864\)

\(\Leftrightarrow4x=840\)

\(\Leftrightarrow x=210\)

Vậy ...

231-(x-6)=1339:13

237-x=103

=>x=237-103=134

Vậy x=134

70-5(2x-3)=45

70-10x+15=45

=>-10x=45-15-70=-40

=>x=4

Vậy x=4

Các caau sau tương tự nhé bn

a, 231 - ( x - 6 ) = 1339 : 13

231 - ( x -6 ) = 103

x - 6 = 231 - 103 = 128

x = 128 + 6 = 134

b, 70 - 5 (2x -3 ) = 45

5 ( 2x -3 ) = 70 - 45 = 25

( 2x -3 ) = 25 : 5 = 5

2x = 5 + 3 = 8

x = 8 : 2 = 4

c, 156 - ( x + 61 ) = 82

x + 61 = 156 - 82 =74

x = 74 - 61

x = 13

d, 6 ( 5x + 35 ) = 330

5x + 35 = 330 : 6 = 55

5x = 55 - 35 = 20

x = 20 : 5 = 4

e, 936-(4x+ 24 ) = 72

4x + 24 = 936 - 72 = 864

4x = 864 - 24 = 840

x = 840 : 4 = 210

Chuc ban hoc tot nhe

a) \(70-5\left(2x-3\right)=45\)

\(70-10x+15=45\)

\(-10x=45-70-15\)

\(-10x=-40\)

\(x=4\)

vay \(x=4\)

 b) \(156-\left(x+61\right)=82\)

\(x+61=156-82\)

\(x+61=74\)

\(x=74-61\)

\(x=13\)

vay \(x=13\)

c) \(6\left(5x+35\right)=330\)

\(30x+210=330\)

\(30x=330-210\)

\(30x=120\)

\(x=4\)

vay \(x=4\)

d) \(936-\left(4x+24\right)=72\)

\(4x+24=936-72\)

\(4x+24=864\)

\(4x=864-24\)

\(4x=840\)

\(x=210\)

vay \(x=210\)

\(70-5.\left(2x-3\right)\)\(=45\)

\(5.\left(2x-3\right)\)\(=\)\(70-45\)

\(5.\left(2x-3\right)\)\(=25\)

\(2x-3=25:5\)

\(2x-3=5\)

\(2x=8\)

\(x=8:2\)

\(x=4\)

\(156-\left(x+61\right)\)\(=82\)

\(x+61=156-82\)

\(x+61=74\)

\(x=74-61\)

\(x=13\)

\(6.\left(5x+35\right)\)\(=330\)

\(5x+35=330:6\)

\(5x+35=55\)

\(5x=55-35\)

\(5x=20\)

\(x=20:5\)

\(x=4\)

\(936-\left(4x+24\right)\)\(=72\)

\(4x+24=936-72\)

\(4x+24=864\)

\(4x=864-24\)

\(4x=840\)

\(x=840:4\)

\(x=210\)

Tìm x :

a) 70 - 5 . ( 2x - 3 ) = 45

           5 . ( 2x - 3 ) = 70 - 45

           5 . ( 2x - 3 ) = 25

                    2x - 3 = 25 : 5

                    2x - 3 = 5

                         2x = 5 + 3

                         2x = 8

                           x = 8 : 2

                           x = 4

b)    156 - ( x + 61 ) = 82

                     x + 61 = 156 - 82

                     x + 61 =  74

                             x = 74 - 61

                             x = 13

c) 6 . ( 5x + 35 ) = 330

             5x + 35 = 330 : 6

             5x + 35 = 55

                     5x = 55 - 35

                     5x = 20

                       x = 20 : 5 

                       x = 4

d) 936 - ( 4x + 24 ) = 72

                  4x + 24 = 936 - 72

                  4x + 24 = 364

                          4x = 364 - 24

                          4x = 340

                            x = 340 : 4

                            x = 85

x=13

x =13

156-(x+61)=82

(X+61) = 156-82

(X+61)=74

X+61  =74

X=74-61

X=13

BÀI DỄ MÀ

156 – ( x + 61) = 82

x + 61 = 156 – 82

x + 61 = 74

x = 74 – 61

x = 13.

a) 156 - ( x + 61 ) = 82

x + 61 = 156 - 82

x + 61 = 74

x = 74 - 61

x = 13

b) 124 + ( 18 - x ) = 317

18 - x = 317 - 124

18 - x = 193

x = 18 - 193

x = -175