a. 8 . 2x - 5 - 32 = 119

8 . 2x - 5 - 9 = 119

8 . 2x - 5 = 119 + 9

8 . 2x - 5 = 128

2x - 5 = 128 : 8

2x -  5 = 16

2x -  5 = 24 (cùng cơ số)

x - 5 = 4

x = 4 + 5; x = 9

b. 5x + 2x = 62 - 50

7x = 36 - 1

7x = 35

x = 5

a. 8 . 2^{x - 5} - 3² = 119

8 . 2^{x - 5} - 9 = 119

8 . 2^{x - 5} = 119 + 9

8 . 2^{x - 5 =} 128

2^{x - 5} = 128 : 8

2^{x -  5} = 16

2^{x -  5} = 2⁴ (cùng cơ số)

x - 5 = 4

x = 4 + 5; x = 9

b. 5x + 2x = 6² - 5⁰

7x = 36 - 1

7x = 35

x = 6

Sai đáp án, 

b. 

x = 5

\(\left(2x-4\right)^4=81\)

\(\left(2x-4\right)^4=3^4\)

\(\Rightarrow2x-4=3\)

\(\Rightarrow2x=7\)

\(\Rightarrow x=\frac{7}{2}\)

vay \(x=\frac{7}{2}\)

\(\left(x-1\right)^5=-32\)

\(\left(x-1\right)^5=\left(-2\right)^5\)

\(\Rightarrow x-1=-2\)

\(\Rightarrow x=-1\)

vay \(x=-1\)

\(\left(2x-1\right)^6=\left(2x-1\right)^8\)

\(\left(2x-1\right)^6-\left(2x-1\right)^8=0\)

\(\left(2x-1\right)^6-\left(2x-1\right)^6.\left(2x-1\right)^2=0\)

\(\left(2x-1\right)^6.\left[1-\left(2x-1\right)^2\right]=0\)

\(\left(2x-1\right)^6\left(1-2x+1\right)\left(1+2x-1\right)=0\)

\(\left(2x-1\right)^6\left(-2x+2\right)\left(2x\right)=0\)

\(\Rightarrow\left(2x-1\right)^6=0\)hoac \(\Rightarrow\orbr{\begin{cases}-2x+2=0\\2x=0\end{cases}}\)

\(\Rightarrow2x-1=0\) hoac \(\Rightarrow\orbr{\begin{cases}x=1\\x=0\end{cases}}\)

\(\Rightarrow x=\frac{1}{2}\)hoac \(\orbr{\begin{cases}x=1\\x=0\end{cases}}\)

hoc moi lop 5

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 :)?)

Bài 1

a) 15 + 4.12 - 3²

=15 + 48 - 9

= 63 - 9

= 54

b) {[(37 + 13) : 5].2 - 45 : 5}.7 - 2022⁰

= [(50 : 5).2 - 9].7 - 1

= (10.2 - 9).7 - 1

= (20 - 9).7 - 1

= 11.7 - 1

= 77 - 1

= 76

Bài 2

a) 13x + 3 = 16

13x = 16 - 3

13x = 13

x = 13 : 13

x = 1

b) 2x - 138 = 2⁴ : 2³

2x = 2 + 138

2x = 140

x = 140 : 2

x = 70

b) (2x)^2 -1 - (3x)^2 + 4=-2

   -5x^2=1

   x^2=-1/5

x không tồn tại

a) \(\left(2x+1\right)^2-\left(2x-3\right)^2=5\Leftrightarrow\left(2x+1-2x+3\right)\left(2x+1+2x-3\right)=5\Leftrightarrow4\left(4x-2\right)=5\Leftrightarrow16x-8=5\Leftrightarrow16x=13\Leftrightarrow x=\dfrac{13}{16}\)b) \(\left(2x-1\right)\left(2x+1\right)-\left(3x-2\right)\left(3x+2\right)=-2\Leftrightarrow4x^2-1-9x^2+4=-2\Leftrightarrow5x^2=5\Leftrightarrow x^2=1\Leftrightarrow x=\pm1\)

TÌM X THUỘC N

A,(3X - 7)⁵=32

(3X - 7)⁵= 2⁵

\(\Rightarrow\)3X - 7 =2

3X = 2 + 7

3X = 9

X = 9: 3

X = 3 thuộc N

Vậy X= 3

a)(3x-7)⁵=32

  (3x-7)⁵=2⁵

=>3x-7=2

3x=2+7

3x=9

x=9:3

x=3 

Vậy...

b)11-(4x+5):3=4

(4x+5):3=11-4

(4x+5):3=7

4x+5=7.3    (. là nhân bn nha)

4x+5=21

4x=21-5

4x=16

x=16:4

x=4

Vâjy....

c)2x=32-1

2x=31

x=31/2

Vậy ...

tk nha bn

(3x-7)⁵=2⁵

=>3x-7=2

    3x   =7-2

    3x   =5

    x    =5:3

  x=5/3

B 121:11-(4x+5):3=4

          11-(4x+5)   =4.3

          11-(4x+5)   =12

                4x-5     =11-12

                4x-5     =-1

                4x        =-1+5

               4x         =4

                  x        =4:4

                  x        =1

2x+1=32

2x=32-1

2x=31

x=31:2

x=31/2

\(\left(1900-2x\right):35-32=16\)

\(\left(1900-2x\right):35=48\)

\(1900-2x=1680\)

\(2x=220\)

\(x=110\)

\(\left(1900-2x\right):35=16+32\)

\(\left(1900-2x\right):35=48\)

\(1900-2x=48.35\)

\(1900-2x=1680\)

\(2x=1900-1680\)

\(2x=220\)

\(x=220:2\)

\(x=110\)

Vậy x=110

(1900-2x):35-32=16

(1900-2x):35=16+32

(1900-2x):35=48

1900-2x=48.35

1900-2x=1680

         2x=1900-1680 

         2x=220

           x=220:2

           x=110

(dấu "."là dấu nhân nha bạn)