\(a,128-3.\left(x+4\right)=23\\ \Rightarrow3.\left(x+4\right)=105\\ \Rightarrow x+4=35\\ \Rightarrow x=31\\ b,\left[\left(4x+28\right).3+55\right]:5=35\\ \Rightarrow\left(4x+28\right).3+55=175\\ \Rightarrow4x+28.3=120\\ \Rightarrow4x+28=60\\ \Rightarrow4x=32\\ \Rightarrow x=8.\)

c) \(\left(12x-4^3\right).8^3=4.8^4\)

\(12x-64=4.8^4:8^3\)

\(12x-64=32\)

\(12x=32+64\)

\(12x=96\)

\(x=\dfrac{96}{12}\)

\(x=8\)

d) \(720:\left[41-\left(2x-5\right)\right]:5=35\)

\(720:\left(41-2x+5\right):5=35\)

\(720:\left(46-2x\right)=35.5\)

\(720:\left(46-2x\right)=175\)

\(46-2x=720:175\)

\(46-2x=\dfrac{144}{35}\)

\(2x=46-\dfrac{144}{35}\)

\(2x=\dfrac{1466}{35}\)

\(x=\dfrac{1466}{35}:2\)

\(x=\dfrac{733}{35}\)

a,

128-3x-12=23

3x=128-12-23

3x=93

x=93:3

= 31

b,

(12x+84+55):5=35

12x+84+55=35.5

12x+84+55=175

12x=175-55-84

12x=36

x=36:12

x=3

de qua

(1)\(2x+23=3^7\div3^4\)

\(2x+23=3^3\)

\(2.x=27-23=4\)

\(x=4\div2\)

\(x=2\)

~~~CÁC CÂU SAU BẠN TỰ LÀM NHÉ~~~

CŨNG KHÔNG KHÓ MẤY ĐÂU^_^ VỚI LẠI HƠI NHIỀU ĐÓ BẠN!!!

~~~HỌC TỐT NHA~~~

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 \(x=14\)

.

a, 128 – 3(x+4) = 23

b,  12 x - 4 3 . 8 3 = 4 . 8 4

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

d, 720:[41 – (2x – 5)] =  2 3 . 5

đùa nhau à

?

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

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

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

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

\(x+4=105:3=35\)

\(x=35-4=31\)

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

\(\left(4x+28\right)\cdot3+55=35\cdot5=175\)

\(\left(4x+28\right)\cdot3=175-55=120\)

\(4x+28=120:3=40\)

\(4x=40-28=12\)

\(x=12:4=3\)

a)120-3(x+4)=23

=>3(x+4)=120-23

=>3(x+4)=97

=>x+4=97:3

=>x+4=\(\frac{97}{3}\)

=>x=\(\frac{97}{3}\)-4

=>x=\(\frac{85}{3}\)

Vậy x=\(\frac{85}{3}\)

b)[(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

Vậyx= 3

c)\((12x-4^3).8^3=4.8^4\)

=>\(12x-64=4.8^4:8^3\)

=>12x-64=4.8

=>12x-64=32

=>12x=96

=>x=96:12

=>x=8

Vậy x=8

d)720:[41-(2x-5)]=2³.5

=>720:[41-2x-5)]=40

=>41-(2x-5)=720:40

=>41-(2x-5)=18

=>2x-5=41-18

=>2x-5=23

=>2x=23+5

=>2x=28

=>x=28:;2

=>x=14

Vậy x=14

a, 120 - 3 [ x+4]=23

     3 [x+4]= 120-23 = 97

      3x = 97-4

      3x= 93

        x= 93:3

        x=31

em bt làm mỗi bài này thui mà ko bt đúng ko