Đề bài có gì đó ko ổn

sai đề

( 3x + 1 )\(^3\)= 64

( 3x + 1 )\(^3\)= 4\(^3\)

=> 3x + 1 = 4

     3x       = 4 - 1

       x       = 3 : 3

       x       = 1

Vậy, x = 1

Cảm ơn bạn

`#040911`

`(x + 5)^3 = (2x)^3`

`\Rightarrow x + 5 = 2x`

`\Rightarrow x + 5 - 2x = 0`

`\Rightarrow 5 + (x - 2x) = 0`

`\Rightarrow 5 - x = 0`

`\Rightarrow x = 5 - 0`

`\Rightarrow x = 5`

Vậy, `x= 5.`

Cảm ơn bạn nha

a) \(1,25^2-0,5^2+3,25^3\)

\(=\left(\frac{5}{4}\right)^2-\left(\frac{1}{2}\right)^2+\left(\frac{13}{4}\right)^3\)

\(=\frac{25}{16}-\frac{1}{4}+\frac{2197}{64}\)

\(=\frac{2281}{64}\)

b) \(1,2+2,4^2-\left(3\frac{1}{2}\right)^2\)

\(=\frac{6}{5}+\left(\frac{12}{5}\right)^2-\left(\frac{7}{2}\right)^2\)

\(=\frac{6}{5}+\frac{144}{25}-\frac{49}{4}\)

\(=\frac{-529}{100}\)

2.2.2.5.5.5.10 = ( 2.5 ) . ( 2.5 ) . ( 2.5 ) . 10 = 10 . 10 . 10 . 10 = 10⁴

2 . 2 . 2 . 2 . 4 . 4 = ( 2.2 ) . ( 2.2 ) . 4 . 4 =  4 . 4 . 4 . 4 = 4⁴

4 . 4 . 8 . 8 =  (2 . 2 ) . ( 2.2 ) . ( 2 . 2 . 2 ) . ( 2. 2 . 2 ) = 2 . 2 .2 . 2 .2 . 2 .2 . 2 .2 . 2  = 2¹⁰

x³ = 125

x = \(\sqrt[3]{125}=5\)

2^x + 4.2^x = 5.2⁵ 

2^x ( 4 + 1 ) = 2⁵ . 5

2^x . 5 = 2⁵ . 5

x = 5

3ⁿ : 9 = 3⁷

3ⁿ : 3² = 3⁷

3^n-2 = 3⁷

n - 2 = 7

n = 7 + 2 = 9

n = { 3 ; 4 ; 5 }

3 mu 2 . 81

2 mu 5 .32

9 mu 3 chia 9

5 mu8chia 25

a) Vì \(-45< -16\) nên \(\left(-\dfrac{45}{17}\right)^{15}< \left(\dfrac{-16}{17}\right)^{15}\)

b) Vì \(21< 23\) nên \(\left(-\dfrac{8}{9}\right)^{21}< \left(-\dfrac{8}{9}\right)^{23}\)

c) \(27^{40}=3^{3^{40}}=3^{120}\)

\(64^{60}=8^{2^{60}}=8^{120}\)

Vì \(3< 8\) nên \(3^{120}< 8^{120}\) hay \(27^{40}< 64^{60}\)

(5x + 9 )³= 216

(5x + 9 )³⁼ 6³

=> 5x+ 9 = 6

     5x      = 6 - 9

     5x      =   - 3

       x      = -3 : 5

       x      =   \(\frac{-3}{5}\)

Chắc là đúng đó. 

Hok tốt nha~