Bài này khử mẫu sẽ tính nhanh hơn.

\(\frac{\left[\left(4x+28\right)3+55\right]}{5}=5\)

\(\Leftrightarrow\frac{\left[\left(4x+28\right)3+55\right]}{5}=\frac{25}{5}\)

\(\Leftrightarrow\left[\left(4x+28\right)3+55\right]=25\)

\(\Leftrightarrow\left[12x+84+55\right]=25\)

\(\Leftrightarrow12x=25-84-55\)(chuyển vế đổi dấu)

\(\Leftrightarrow12x=-114\Leftrightarrow x=-\frac{19}{2}\)

\(\frac{\left[\left(4x+28\right).3+55\right]}{5}=5\)

\(\Leftrightarrow\left(4x+28\right).3+55=25\)

\(\Leftrightarrow\left(4x+28\right).3=-30\)

\(\Leftrightarrow4x+28=-10\)

\(\Leftrightarrow4x=-38\)

\(\Leftrightarrow x=-9,5\)

Vậy\(x=-9,5\)

Ddaeng

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

(4x+28)*3+55=25

(4x+28)*3=25-55

(4x+28)*3=-30

4x+28=-30:3

4x+28=-10

4x=-10-28

4x=-38

x=-38:4

x=-9,5

⇒ ( 4x + 28 ) . 3 + 55  = 35 . 5

 ⇒ ( 4x + 28 ) . 3 + 55 = 175

  ⇒ ( 4x + 28 ) . 3 = 175 - 55

  ⇒ ( 4x + 28 ) .3 = 120

   ⇒  4x + 28 = 120 : 3

    ⇒ 4x + 28 = 40

   ⇒  4x = 40 -  28

    ⇒ 4x = 12

     ⇒ x = 12: 4

⇔ x = 3.

Vậy x= 3.

\(\left[\left(4x+28\right)\times3+55\right]\div5=35\)

\(\left(4x+28\right)\times3+55=175\)

\(12x+84+55=175\)

\(12x=175-55-84\)

\(12x=36\)

\(x=3\)

`@` `\text {Ans}`

`\downarrow`

`b)`

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

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

`=> (4x + 28)*3 + 55 = 175`

`=> (4x + 28)*3 = 175 - 55`

`=> (4x + 28)*3 =120`

`=> 4x + 28 = 120 \div 3`

`=> 4x + 28 = 40`

`=> 4x = 40 - 28`

`=> 4x = 12`

`=> x = 12 \div 4`

`=>x = 3`

Vậy, `x = 3.`

=>[12x+84+55]=175

=>12x=175-84-55=120-84=36

=>x=36/12=3

<=>[12x+84+55]:5=35

<=>[12x+139]:5=35

<=>12x+139=35.5

<=>12x=175-139

<=>x=3

kết quả là-11

x=3 nha ban :))))))))))

t i c k nha

mik tính đc 11 bn nha 

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

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

=> (4x + 28).3 = 120

=> 4x + 28 = 40

=> 4x = 12

=> x = 3

vậy_

[( 4x + 48 ) . 3 + 55 ] : 5 = 35

( 4x + 48 ) . 3 + 55 = 35 . 5 = 175

4x + 48 = 175 : 3 = 175/3

4x = 175/3 - 48 = 31/3

x = 31/3 : 4 = 31/12=2/7/12

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

[(4x+28).3+55]=35.5

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

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

(4x+28).3=120

4x+28=120:3

4x+28=40

4x=40-28

4x=12

x=12:4

x=3

k cho mik nhoa bn nha!

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

   ( 4x + 28 ) . 3 + 55       = 175

   ( 4x + 28 ) . 3               = 120

   ( 4x + 28 )                    = 40

      4x                             = 12

        x                              = 3

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