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:_)

Ta có : \(32^{17}+16^{21}-2^{82}=\left(2^5\right)^{17}+\left(2^4\right)^{21}-2^{82}=2^{85}+2^{84}-2^{82}\)

                                                    \(=2^{80}.2^5+2^{80}.2^4-2^{80}.2^2=2^{80}.\left(2^5+2^4-2^2\right)=2^{80}.44⋮44\)

Vậy \(32^{17}+16^{21}-2^{82}⋮44\left(đpcm\right)\)

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) 2115 : x = 21

=> x = 2115 : 21 = \(\frac{705}{7}\) ( sai đề )
b) \(\left(9\times x-21\right):3=2\)

=> \(\left(9\times x-21\right)=2\times3=6\)

=> \(9\times x=6+21=27\)

=> \(x=27:9=3\)

Vậy x = 3

c) 231 + ( 312 - x ) = 531

=> 231 + 312 - x = 531

=>. 543 - x = 531

=> x = 543 - 531 = 12

Vậy x = 12

a) 2115 : x = 21

x= 705/7

b) ( 9 * x - 21) : 3 = 2

9 * x  - 21 = 6

9 * x = 27

x = 3

c) 231 + ( 312 - x) = 531

231 + 312 - x = 531

543 - x = 531

x =12

a. 2115 : x = 21

               x = 2115 : 21

               x = 705/7

b. ( 9 . x - 21 ) : 3 = 2

      9x : 21 = 6

      9x = 27

        x = 3

c. 231 + ( 312 - x ) = 531

                312 - x = 300

                         x= 12

a, (9.x-21) : 3 = 2

=>9x-21=6

=>9x=27

=>x=3

b, (x-39)-21=0

=>x-39-21=0

=>x-60=0

=>x=60

c, 231+(312-x)=531

=>231+312-x=531

=>543-x=531

=>x=543-531

=>x=12

d, 53.(9-x)=53

=>9-x=1

=>x=8

a/ \(\frac{\left(9x-21\right)}{3}=2\)

\(\Rightarrow9x-21=2\cdot3=6\)

\(\Rightarrow9x=6+21=27\)

\(\Rightarrow x=\frac{27}{9}=3\)

b/ \(\left(x-39\right)-21=0\)

\(\Rightarrow x-39=0+21=21\)

\(\Rightarrow x=21+39=60\)

c/ \(231+\left(312-x\right)=531\)

\(\Rightarrow312-x=531-231=300\)

\(\Rightarrow x=312-300=12\)

d/ \(53\cdot\left(9-x\right)=53\)

\(\Rightarrow9-x=\frac{53}{53}=1\)

\(\Rightarrow x=9-1=8\)

a) ( 9 . x - 21 ) : 3 = 2

      9 . x - 21 = 6

      9 . x = 6 + 21

      9 . x = 27

      x = 27 : 9

      x = 3

b) ( x - 39 ) - 21 = 0

     x - 39 = 21

     x = 21 + 39

     x = 60

c) 231 + ( 312 - x ) = 531

   312 - x = 531 - 231

   312 - x = 300

   x = 312 - 300

   x = 12

d) 53 . ( 9 - x ) = 53

    9 - x = 1

    x = 9 - 1

    x = 8

=> 311 - x + 82 = 46 + x - 21

=> 393 - x = x + 25

=> 2x = 368

=> x = 184

\(\frac{x+11}{115}+\frac{x+22}{104}=\frac{x+33}{93}+\frac{x+44}{82}\)

\(\Leftrightarrow\frac{1+\left(x+11\right)}{115}+\frac{1+\left(x+22\right)}{104}=\frac{1+\left(x+33\right)}{93}+\frac{1+\left(x+44\right)}{82}\)

\(\Leftrightarrow\frac{x+126}{115}+\frac{x+126}{104}=\frac{x+126}{93}+\frac{x+126}{82}\)

\(\Leftrightarrow\left(x+126\right).\left(\frac{1}{115}+\frac{1}{104}+\frac{1}{93}+\frac{1}{82}\right)=0\)

\(\Leftrightarrow x+126=6\Leftrightarrow x=-126\)vì\(\frac{1}{115}+\frac{1}{104}+\frac{1}{93}+\frac{1}{82}\ne0\)

vậy x=-126

= 21

KB VÀ K CHO MÌNH NHÉ

122 + 234 - 231 x 12 x 0 + 21 = 377

Ô MÌNH NHẦM  , PHẢI LÀ 377

truong ngoc huyen toa ncopy bai cua nguoi khac chu trinh ga cong nghiep nhu no lam sao lam duoc bai nay

311-x+82=46+(x-21)

=>311+82-46+21=2x

x=184

tik nha Wan đẹp zai