a) x = 3

b) x = 53

c) x = 2024

d) x = 6

1) x = 4/5 - 1/3

x = 7/15

2) 5/3.x=1/21

x=1/35

3) -12/13.x = 1/13

x=-1/12

7) th1: x-1=2/3

x = 5/3

Th2: x - 1 = -2/3

x=1/3

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

5( x - 3 ) = 70 - 45 = 25

x - 3 = 25 : 5 = 5

x = 5 + 3 = 8

b) (2x - 1 )⁴ = 3 . 6² - 27

(2x - 1 )⁴ = 3 . 36 - 27

(2x - 1 )⁴ = 81

 Ta thấy 81  = 3⁴ vậy suy ra (2x - 1)⁴ = 3⁴

 Để vế trong ngoặc tròn (2x - 1 ) = 3 thì x cần bằng 2

Thử lại : 2 . 2 - 1 = 4 - 1 = 3

Vậy x = 2

c) 3x³ +  43 = 10² - 33

3x³ + 43 = 100 - 33 = 67

3x³ = 67 + 43 = 110 ( Đoạn này đề bài sai hay tao sai z :)?)

Ta có:\(\frac{12-3x}{32}=\frac{6}{4-x}\)

\(\Leftrightarrow\left(12-3x\right)\left(4-x\right)=32.6\)

\(\Leftrightarrow3\left(4-x\right)\left(4-x\right)=192\)

\(\Leftrightarrow\left(4-x\right)^2=64\)

\(\Leftrightarrow\orbr{\begin{cases}4-x=8\\4-x=-8\end{cases}}\)

\(\Leftrightarrow\orbr{\begin{cases}x=12\\x=-4\end{cases}}\)

Vậy x = 12 hoặc x = -4

Linz

\(\frac{12-3x}{32}=\frac{6}{4-x}\)

\(\Leftrightarrow\left(12-3x\right)\left(4-x\right)=192\)

\(\Leftrightarrow3\left(4-x\right)\left(4-x\right)=192\)

\(\Leftrightarrow\left(4-x\right)^2=64\)

\(\Rightarrow\orbr{\begin{cases}4-x=8\\4-x=-8\end{cases}\Rightarrow\orbr{\begin{cases}x=-4\\x=12\end{cases}}}\)

\(\frac{12-3x}{32}=\frac{6}{4-x}\left(đkxđ:x\ne4\right)\)

\(< =>\left(12-3x\right)\left(4-x\right)=32.6\)

\(< =>3\left(4-x\right)\left(4-x\right)=32.6\)

\(< =>\left(4-x\right)^2=\frac{32.6}{3}=32.2=64\)

\(< =>\orbr{\begin{cases}4-x=8\\4-x=-8\end{cases}< =>\orbr{\begin{cases}x=-4\\x=12\end{cases}}}\)

(82 - 5.x) : 13 - 4 = 0

(82 - 5.x) : 13 = 0 + 4

(82 - 5.x) : 13 = 4

(82 - 5.x) = 4 . 13

(82 - 5.x) = 52

5.x  = 82 - 52

5.x = 30

x = 30 : 5 = 6

(32 . 45) : 2 = (x + 70) : 14 - 40

720 = (x + 70) : 14 - 40

(x + 70) : 14 = 720 + 40

(x + 70) : 14 = 760

(x + 70) = 760 . 14

(x + 70) = 10640

x = 10640 - 70

x = 10570

Tìm x biết : 

( 82 - 5 . x ) : 13 - 4 = 0 

( 82 - 5 . x ) : 13 = 0 + 4 

( 82 - 5 . x )  : 13 = 4 

82 - 5 . x = 4 × 13 

82 - 5 . x = 52 

5 . x = 82 - 52 

5 . x = 30 

x = 30 : 5 

x = 6

Vậy x = 6

  a) ( 82- 5x ): 13- 4= 0

( 82- 5x ): 13           = 0+ 4

( 82- 5x ): 13           = 4

82- 5x                      = 4. 13

82- 5x                      = 52

5x                            =  82- 52

5x                            = 30

x                              = 30: 5

x                              = 6

  b) ( 32. 45 ): 2= ( x+ 70 ): 14- 40

1440: 2             = ( x+ 70 ): 14- 40

720                    = ( x+ 70): 14- 40

   => ( x+ 70 ): 14= 720+ 40

( x+ 70 ): 14       = 760

x+ 70                  = 760. 14

x+ 70                  = 10640

x                         = 10640- 70

x                         = 10570

a) Ta có : 2 x : 2 2 = 2 5  nên x = 7.

b) Ta có: 3 x : 3 2 = 3 5  nên x = 7.

c) Ta có : 4 4 : 4 x = 4 2  nên x = 2.

\(\frac{12-3x}{32}=\frac{6}{4-x}\)

\(\Leftrightarrow\left(12-3x\right)\left(4-x\right)=6.32\)

\(\Leftrightarrow48-12x-12x+3x^2=192\)

\(\Leftrightarrow3x^2-24x-144=0\)

\(\left(a=3;b=-24;c=-144\right)\)

\(\Delta=b^2-4ac=\left(-24\right)^2-4.3.\left(-144\right)=2304>0\)

\(\sqrt{\Delta}=\sqrt{2304}=48\)

\(x_1=\frac{-b+\sqrt{\Delta}}{2a}=\frac{24+48}{2.3}=12\)

\(x_2=\frac{-b-\sqrt{\Delta}}{2a}=\frac{24-48}{2.3}=-4\)\

Vậy x1 = 12 ; x2 = -4 

Học tốt !!! :) 

a) -45 : ( 3x - 17 ) = 3²

3x - 17 = -45 : 9

3x - 17 = -5

3x = 12

x = 4

b) \(\left(2x-8\right)\left(-2x\right)=0\)

\(\Rightarrow\orbr{\begin{cases}2x-8=0\\-2x=0\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x=4\\x=0\end{cases}}\)

Vậy.....

c) \(72:\left|4x-3\right|=2^3\)

\(\left|4x-3\right|=9\)

\(\Rightarrow\orbr{\begin{cases}4x-3=9\\4x-3=-9\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x=3\\x=\frac{-3}{2}\end{cases}}\)

Vậy.....