a) \(\left[\left(4x+28\right).3+55\right]:5=35\)

\(\Leftrightarrow\left(4x+28\right).3+55=35.5\)

\(\Leftrightarrow\left(4x+28\right).3+55=175\)

\(\Leftrightarrow\left(4x+28\right).3=175-55\)

\(\Leftrightarrow\left(4x+28\right).3=120\)

\(\Leftrightarrow4x+28=120:3\)

\(\Leftrightarrow4x+28=40\)

\(\Leftrightarrow4x=40-28\)

\(\Leftrightarrow4x=12\)

\(\Leftrightarrow x=12:4\)

\(\Leftrightarrow x=3\)

Vậy \(x=3\)

b) \(\left(12x-4^3\right).8^3=4.8^4\)

\(\Leftrightarrow12x-4^3=4.8^4:8^3\)

\(\Leftrightarrow12x-4^3=4.8^{4-3}\)

\(\Leftrightarrow12x-4^3=4.8\)

\(\Leftrightarrow12x-4^3=32\)

\(\Leftrightarrow12x-64=32\)

\(\Leftrightarrow12x=32+64\)

\(\Leftrightarrow12x=96\)

\(\Leftrightarrow x=96:12\)

\(\Leftrightarrow x=8\)

Vậy \(x=8\)

c) \(720:\left[41-\left(2x-5\right)\right]=2^3.5\)

\(\Leftrightarrow720:\left[41-\left(2x-5\right)\right]=8.5\)

\(\Leftrightarrow720:\left[41-\left(2x-5\right)\right]=40\)

\(\Leftrightarrow41-\left(2x-5\right)=720:40\)

\(\Leftrightarrow41-\left(2x-5\right)=18\)

\(\Leftrightarrow2x-5=41-18\)

\(\Leftrightarrow2x-5=23\)

\(\Leftrightarrow2x=23+5\)

\(\Leftrightarrow2x=28\)

\(\Leftrightarrow x=28:2\)

\(\Leftrightarrow x=14\)

Vậy \(x=14\)

[ { 4 x X + 28 } x 3 + 55 ] : 5 = 35

[ { 4 x X + 28 } x 3 + 55 ] = 35 x 5

[ { 4 x X + 28 } x 3 + 55 ] = 175

{ 4 x X + 28 } x 3 = 175 - 55

{ 4 x X + 28 } x 3 = 120

4 x X + 28 = 120 : 3

4 x X + 28 = 40

4 x X = 40 - 28

4 x X = 12

X = 12 : 4

X = 3

(4*X+28)*3+55=35*5

=>(4*X+28)*3+55=175

=>(4*X+28)*3=120

=>4*X+28=40

=>4*X=12

=>X=3
 

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

x-3=70-5-45

x-3=20

x=20-3=17

b.2x-138=8.9

2x-138=72

2x=72+138

2x=210

x=210:2=105

c.10+2n=16

2n=16-10

2n=6

n=6:3=2

d.[(4x+28).3+55]:5=35

[(4x+28).3+55]=35x5=175

4x+28=(175-55):3

4x+28=40

4x=40-28=12

x=12:4=3

Dung thi k mk nha

Chuc bn hoc gioi nha

[(4 : x + 28).3+55]:5=35

(4:x+28).3+55=35.5=175

(4:x+28).3=175-55=120

4:x+28=120:3=40

4:x=40-28=16

x=4:16

=>x=0,25

=> (4:x+28).3+55=35.5

=> (4:x+28).3=175-55

=> 4:x+28=120:3

=> 4:x=40-28

=> 4:x=12

=> x=4:12

=> x=\(\frac{1}{3}\)

[(4:X+28).3+55]:5=35

[(4:x+28).3+55]   =35.5

[(4:x+28).3+55]   =175

[(4:x+28).3]        =175-55

[(4:x+28).3]        =120

   (4:x+28)          =120:3

    4:x+28          =40

    4:x                =40-28

    4:x                 =12

                        x=4:12

                        x=1/3

(4*x+28)*(3+55) :5=35

         (4*x+28)*58 =35.5

             (4*x+28)*58= 175

                    4*x+28=\(\frac{175}{58}\)

                   4 * x = \(\frac{175}{58}-28\)

                  4 * x = \(\frac{-1449}{58}\)

                      x = \(\frac{-1449}{58}:4=\frac{-1449}{232}\)

{ ( 4 . x + 28 ) . 3 + 55 }      = 35 . 5

{ ( 4 . x + 28 ) . 3 + 55 }      = 175

{ ( 4 . x + 28 ) . 3 }              = 175 - 55

{ ( 4 . x + 28 ) . 3 }              = 120

{ ( 4 . x + 28 ) }                   = 120 : 3

     4 . x + 28                       = 40

     4 . x                               = 40 - 28

     4 . x                               = 12

          x                               = 12 : 4

          x                               = 3

dương bạn lớp mấy ở đâu học trường nào

\(\left[\left(4x+28\right)\cdot3+55\right]:5=35\)

\(\Leftrightarrow\left(4x+28\right)\cdot3+55=35\cdot5\)

\(\Leftrightarrow\left(4x+28\right)\cdot3+55=175\)

\(\Leftrightarrow\left(4x+28\right)\cdot3=175-55\)

\(\Leftrightarrow\left(4x+28\right)\cdot3=120\)

\(\Leftrightarrow4x+28=120:3\)

\(\Leftrightarrow4x+28=40\)

\(\Leftrightarrow4x=40-28\)

\(\Leftrightarrow4x=12\)

\(\Leftrightarrow x=12:4\)

\(\Leftrightarrow x=3\)

a) \(128-3\left(x+4\right)=23\)

\(\Rightarrow3\left(x+4\right)=128-23\)

\(\Rightarrow3\left(x+4\right)=105\)

\(\Rightarrow x+4=35\)

\(\Rightarrow x=35-4\)

\(\Rightarrow x=31\)

b) \(\left[\left(4x+28\right)\cdot3+55\right]:5=35\)

\(\Rightarrow\left(4x+28\right)\cdot3+55=35\cdot5\)

\(\Rightarrow\left(4x+28\right)\cdot3+55=175\)

\(\Rightarrow\left(4x+28\right)\cdot3=120\)

\(\Rightarrow4x+28=40\)

\(\Rightarrow4x=12\)

\(\Rightarrow x=3\)

a, \(128-3\left(x+4\right)=23\)

\(=>3\left(x+4\right)=128-23\)

\(=>3\left(x+4\right)=105\)

\(=>x+4=105:3\)

\(=>x+4=35\)

\(=>x=35-4\)

\(=>x=31\)

b, \(\left[\left(4x+28\right).3+55\right]:5=35\)

\(=>\left(4x+28\right).3+55=35.5\)

\(=>\left(4x+28\right).3+55=175\)

\(=>\left(4x+28\right).3=175-55\)

\(=>\left(4x+28\right).3=120\)

\(=>4x+28=120:3\)

\(=>4x+28=40\)

\(=>4x=40-28\)

\(=>4x=12\)

\(=>x=12:4\)

\(=>x=3\)

\(#WendyDang\)

a) 128 - 3 (x + 4) =23

      3.( x + 4) = 128 -23

      3. ( x + 4) =  105

      x + 4 = 105 :3

      x + 4 =  35

      x = 35 -4

     x = 31

a: =>3(x+4)=115

=>x+4=115/3

hay x=103/3

b: =>\(8^3\cdot\left(12x-64\right)=4\cdot8^4\)

\(\Leftrightarrow12x-64=32\)

=>12x=96

hay x=8

c: \(\Leftrightarrow\left(4x+28\right)\cdot23+55=175\)

=>(4x+28)x23=120

=>4x+28=120/23

=>4x=-524/23

hay x=-131/23