a/ 12x - 33 = 3^{2 .} 3²

=> 12x - 33 = 3⁵ = 243

=> 12x = 243 + 33 = 276

=> x = 276 : 12 = 23

b/ 148 + (78 + x) = 244

=> 78 + x = 148 - 244 = -96

=> x = -96 - 78 = -174

c/ 45 - x = 49 + 52

=> 45 - x = 101 

=> x = 45 - 101 = -56

d/ 707 - 3(x + 34) = 407

=> 3(x + 34) = 707 - 407 = 300

=> x + 34 = 300 : 3 = 100

=> x = 100 - 34 = 66

e/ 25.3 - x = 104

=> 75 - x = 104

=> x = 75 - 104 = -29

Giải:

Bài 1:

\(707-3\left(x+3\right)=407\)

\(\Leftrightarrow3\left(x-3\right)=300\)

\(\Leftrightarrow x+3=100\)

\(\Leftrightarrow x=97\)

Vậy \(x=97\).

Bài 2:

a) \(143-43.\left[\left(25:5\right)^2-5^2\right]\)

\(=143-43.\left(5^2-5^2\right)\)

\(=143-43.1\)

\(=143-43=100\)

b) \(7:7+49\left(2^3.15-5.4\right)\)

\(=1+49.\left(120-20\right)\)

\(=1+49.100\)

\(=4901\)

c) \(\left(2^3.9^4+9^3.45\right):\left(9^2.10-9^2\right)\)

\(=\left(8.9^4+9^4.5\right):\left(9^2.10-9^2\right)\)

\(=\left[9^4\left(8+5\right)\right]:\left[9^2\left(10-1\right)\right]\)

\(=9^4.13:9^3\)

\(=9.13=117\)

Chúc bạn học tốt!

a) x = 74    

b) x = 5 

c) x = 3      

d) x = 14

lx đb

lỗi

lỗi òi

707 - 3( x + 3⁴ ) = 407

=>  3( x + 81 ) = 300

=> x + 81 = 100

=> x = 19

127 + 3( x + 17 ) = ( 4⁷ : 4⁵ )²

=> 3( x + 17 )  = ( 4² )² - 127

=> 3( x + 17 ) = 256 - 127

=> 3( x + 17 ) = 129

=>   x + 17  43

=> x = 26

x - 6 - ( 48 - 24. 2 : 6 - 3 ) = 100

x - 6 - ( 48 - 2 - 3 ) = 100

x - 6 - 43 = 100

x - 49 = 100

x = 149

[ ( 6x - 39 ) : 3 ] . 28 = 5628

  ( 6x - 39 ) : 3         = 201

    6x - 39                = 603

    6x                       = 642

     x                        = 107

Chúc em hok tốt 

Study well 

\(707-3.(x+3^4)=407\)                        

\(\Rightarrow\)\(707-3.(x+81)=407\)                   

\(\Rightarrow\)\(3.(x+81)=707-407\)

\(\Rightarrow\)\(3.\left(x+81\right)=300\)

\(\Rightarrow\)\(\left(x+81\right)=300:3\)

\(\Rightarrow\)\(\left(x+81\right)=100\)

\(\Rightarrow\)                  \(x=100-81\)

Xin lỗi vì tôi có việc bận nên tí nữa sẽ làm tiếp

\(\Rightarrow\)                  \(x=19\)

707-3.(x+3mũ4)=407

3.(x+81)=707-407

3.(x+81)=300

(x+81)=300:3

(x+81)=100

x=100-81

x=19

127+3.(x+17)=(16 384:1024)mũ2

127+3.(x+17)=16mũ2

127+3.(x+17)=256

3.(x+17)=256-127

3.(x+17)=129

(x+17)=129:3

x+17=43

x=43-17

x=26

X-6-(48-24.2;6-3)=100

x-(48-24.2:6-3)=100+6

x-(48-24.2:6)=106+3

x-(48-24.2)=109.6

x-(48-24)=654:2

x-48=327-24

x=303+48

x=351

[(6.X-39):3].28=5 628

[(6.x-39):3]=5 628:28

(6.x-39)=201.3

6.x-39=603

x-39=603;6

x=100,5+39

x=139.5

phép cuối mình ra số thập phân

`Answer:`

`\frac{x-1}{34}+\frac{x-2}{34}=\frac{x-3}{32}+\frac{x-4}{31}`

`<=>\frac{x-1}{34}-1+\frac{x-2}{33}-1=\frac{x-3}{32}-1+\frac{x-4}{31}-1`

`<=>\frac{x-35}{34}+\frac{x-35}{33}=\frac{x-35}{32}+\frac{x-35}{31}`

`<=>(x-35)(\frac{1}{34}+\frac{1}{33}-\frac{1}{32}-\frac{1}{31})=0`

`<=>x-35=0`

`<=>x=35`

x = 4242

a ) x ∈ ± 23 28 . b ) x ∈ − 23 6 ; 35 6 . c ) x ∈ − 17 60 ; 97 60 . d ) x ∈ 67 140 ; 143 140 .