(x-14)-20=5

=> x-14 = 25

=> x = 39

Các dạng toán như này lớp 6 ai cũng làm được cả * lười vừa thôi*

( x - 14 ) - 20 = 5

 x - 14 = 5 + 20

 x - 14 = 25

 x = 25 + 14

 x = 39

128 + ( 202 - x ) = 330

           [ 202 - x ] = 330 - 128

             202 - x = 202

                      x = 202 - 202

                      x = 0

( x - 120 ) x 9 = 450

[ x - 120 ] = 450 : 9

 x - 120 = 50

 x = 50 + 120

 x = 170

x - 320 : 32 = 25 x 16

x - 320 : 32 = 400

x - 320 = 400 x 32

x - 320 = 12800

x = 12800 + 320

x = 13120

25 - ( 2x +10 ) = 5

        [ 2x + 10] = 25 - 5

          2x + 10 = 20

          2x = 20 - 10

          2x = 10

            x = 10 : 2

            x = 5

315 - ( 135 - x ) = 215

          [ 135 - x ] = 315 - 215

          [ 135 - x ] = 100

                      x = 135 - 100

                      x = 35

x : 2 + 21 : 3 = 37

x : 2 + 21 = 37 x 3

x : 2 + 21 = 111

x : 2 = 111 - 21

x : 2 = 90

x = 90 x 2

x = 180

4 x ( x + 100 ) = 800

      [ x + 100 ] = 800 : 4

      [ x + 100 ] = 200

       x = 200 - 100

       x = 100

504 : ( 16 - 5x ) = 72

          [ 16 - 5x ] = 504 : 72

           [ 16 - 5x ] = 7

                     5x = 16 - 7

                     5x = 9

                       x = \(\dfrac{9}{5}\)

( x - 5 ) : 7 + 3 = 20

[ x - 5 ] : 7 = 20 - 3

[ x - 5 ] : 7 = 17

[ x - 5 ] = 17 x 7

 x - 5 = 119

 x = 119 + 5

 x = 124

a) 320 x 63 - 16 x 20 + 32 x 370

= 320 x 63 - 320 x + 320 x 37

= 320 x ( 63 - 1 + 37 )

= 320 x 99 

= 320 x ( 100 - 1 )

= 320 x 100 - 320

= 32000 - 320 = 31 680

b) 35 x 61 + 215 x 5 + 35 x 39 + 57 x 25

= 5 x 427 + 5 x 215 + 5 x 273 + 5 x 285

= 5 x ( 427 + 215 + 273 + 285 ) 

= 5 x 1200 = 6000

c) 34 x 24 - 94 x 6 + 83 x 48 - 47 x 88

= 204 x 4 - 4 x 141 + 996 x 4 - 1034 x 4

= 4 x ( 204 - 141 + 996 - 1034 )

= 4 x 25 = 100

2, 

a) \(315-\left(135-x\right)=215\)

\(\Rightarrow135-x=315-215\)

\(\Rightarrow135-x=100\)

\(\Rightarrow x=135-100\)

\(\Rightarrow x=35\)

b) \(x-320:32=25\cdot16\)

\(\Rightarrow x-10=5^2\cdot4^2\)

\(\Rightarrow x-10=20^2\)

\(\Rightarrow x-10=400\)

\(\Rightarrow x=410\)

c) \(3\cdot x-2018:2=23\)

\(=3\cdot x-1009=23\)

\(\Rightarrow3\cdot x=1032\)

\(\Rightarrow x=1032:3\)

\(\Rightarrow x=344\)

d) \(280-9\cdot x-x=80\)

\(\Rightarrow280-x\cdot\left(9+1\right)=80\)

\(\Rightarrow280-10\cdot x=80\)

\(\Rightarrow10\cdot x=280-80\)

\(\Rightarrow10\cdot x=200\)

\(\Rightarrow x=20\)

e) \(38\cdot x-12\cdot x-x\cdot16=40\)

\(\Rightarrow x\cdot\left(38-12-16\right)=40\)

\(\Rightarrow x\cdot10=40\)

\(\Rightarrow x=40:10\)

\(\Rightarrow x=4\)

bài 1 cậu ko giải giúp mình dc à

x - 320 : 32 = 25 . 16

x - 10 = 400

x = 400 + 10

x = 410

\(=>x=\left(320:32\right)+\left(25.26\right)=10+400=410\)

\(x-10=400\)

\(x=400+10\)

\(x=410\)

120 x 64 + 320 - 25 x 4 x 16

= 120 x 64 + 64 x 5 - 25 x 64

= 64 x ( 120 + 5 - 25 )

= 64 x 100

= 6400

mk đúng đó

120 x 64 + 320 - 25 x 4 x 16 = 6400

k cho mk nha

120 x 64 + 320 - 25 x 4 x 16 = 7680 + 320 - 100 x 16

                                              = 8000 - 1600 = 6400

120 x 64 + 320 - 25 x 4 x 16 = 120 x 4 x 16 + 20 x 16 - 100 x 16

= 480 x 16 + 20 x 16 - 100 x 16

= 16 x (480 + 20 - 100)

= 16 x 400

= 6400

Bài 1: Thực hiện các phép tính sau:

\(a)\)Chưa rỏ đề

\(b)\)\(5025\div5-25\div5\)

\(=\)\(1005-5\)

\(=\)\(1000\)

\(c)\)\(218-180\div2\div9\)

\(=\)\(218-10\)

\(=\)\(208\)

\(d)\)\(\left(328-8\right)\div32\)

\(=\)\(320\div32\)

\(=\)\(10\)

Bài 1:

a) ( Tôi không nhìn rõ đầu bài )

b) 5025  :  5  -  25  :  5

=  ( 5025  -  25 )  :  5

=        5000   :   5

=       1000

c)   218  -  180  :  2  :  9

=     218   -    180  :  (  2  .  9 )

=      218    -    180   :  18

=       218    -    10

=       208

d)   (  328  -  8  )  :  32

=      320   :   32

=     10 

Bài 2: Thực hiện phép tính:

\(a)\)\(27.75+25.27-150\)

\(=\)\(27.\left(75+25\right)-150\)

\(=\)\(27.100-150\)

\(=\)\(2700-150\)

\(=\)\(2550\)

\(b)\)\(12\div\left\{400\div\left[500-\left(125+25.7\right)\right]\right\}\)

\(=\)\(12\div\left\{400\div\left[500-\left(125+175\right)\right]\right\}\)

\(=\)\(12\div\left\{400\div\left[500-300\right]\right\}\)

\(=\)\(12\div\left\{400\div200\right\}\)

\(=\)\(12\div2\)

\(=\)\(6\)

\(c)\)\(13.17-256\div16+14\div7-1\)

\(=\)\(221-16+2-1\)

\(=\)\(206\)

\(d)\)\(18\div3+182+3.\left(51\div17\right)\)

\(=\)\(6+182+3.3\)

\(=\)\(6+182+9\)

\(=\)\(197\)

`@` `\text {Ans}`

`\downarrow`

`a)`

`4x = 320 \div 16`

`=> 4x = 20`

`=> x = 20 \div 4`

`=> x=5`

Vậy, `x=5`

`b)`

`(x-10) \div 5 = 2`

`=> x - 10 = 2*5`

`=> x - 10 = 10`

`=> x = 10 + 10`

`=> x=20`

Vậy, `x=20`

`c)`

`(20+x) \div 5 = 25`

`=> 20+x = 25*5`

`=> 20+x = 125`

`=> x = 125 - 20`

`=> x = 105`

Vậy, `x=105.`

`@` `\text {Kaizuu lv uuu}`

a) x = 34             

b) x= 5                

c) x = 35              

d) x = 0

e) x = 410            

f) x= 170