(3.x)^2 : 3^3=243

9.x^2 : 27=243

9.x^2=243.27

9.x^2=6561

x^2=6561:9

x^2=729

X=27

3x*3^x+1=243

=>3^x+2=243

=>3^x+2=3⁵

=>x+2=5

=>x=3

a) \(2^x\cdot4=16\)

\(\Rightarrow2^x=16:4\)

\(\Rightarrow2^x=4\)

\(\Rightarrow2^x=2^2\)

\(\Rightarrow x=2\)

b) \(3^x\cdot3=243\)

\(\Rightarrow3^x=243:3\)

\(\Rightarrow3^x=81\)

\(\Rightarrow3^x=3^4\)

\(\Rightarrow x=4\)

a) 3⁵= 243

b)5³=125

tiếp theo bn tự tính nhé

a) \(\left(2x-1\right)^5=243\)

\(\left(2x-1\right)^5=3^5\)

\(\Rightarrow2x-1=3\)

\(2x=3+1\)

\(2x=4\)

\(x=\frac{4}{2}\)

\(x=2\)

Vậy .......

b) \(\left(3x+2\right)^3=125\)

\(\left(3x+2\right)^3=5^3\)

\(\Rightarrow3x+2=5\)

\(3x=5-2\)

\(3x=3\)

\(x=\frac{3}{3}=1\)

Vậy ..........

trả lời giúp mình chiều nay mình đi học thêm rồi . có ai giúp mình mình cảm ơn nhiều

\(3x.\left(\frac{1}{3}\right)^3.9=243\) 

\(\Leftrightarrow3x.\frac{1}{3}=243\) \(\Leftrightarrow3x=729\Leftrightarrow x=243\)

3x . (1/3)^3 . 9 = 243

<=> 3x . 1/27 . 9 = 243

<=> 1x = 243

<=> x = 243

Vậy x = 243

(2x - 3)²=16

(2x-3)²=4²

=>2x-3=4 hoặc 2x-3=-4

=>2x=7 hoặc 2x=-1

=>x=7/2 hoặc x=-1/2

( 3x - 2 )⁵ = -24³ đề đúng phải là ( 3x - 2 )⁵=-243

`@` `\text {Ans}`

`\downarrow`

`2^x = 16`

`=> 2^x = 2^4`

`=> x = 4`

Vậy, `x = 4.`

____

`2^x*16 = 1024`

`=> 2^x =`\(2^{10}\div2^4\)

`=> 2^x = 2^6`

`=> x = 6`

Vậy, `x = 6`

______

`2^x - 26 = 6`

`=> 2^x = 6 + 26`

`=> 2^x = 32`

`=> 2^x = 2^5`

`=> x = 5`

Vậy, `x = 5`

`3^x*3 = 243`

`=> 3^x * 3 = 3^5`

`=> 3^x = 3^5 \div 3`

`=> 3^x = 3^4`

`=> x = 4`

Vậy, `x = 4.`

a) \(3^{2x-1}=243\)

\(\Leftrightarrow3^{2x-1}=3^5\)

\(\Leftrightarrow2x-1=5\)

\(\Leftrightarrow2x=5+1\)

\(\Leftrightarrow2x=6\)

\(\Leftrightarrow x=\dfrac{6}{2}\)

\(\Leftrightarrow x=3\)

Vậy \(x=3\)

b) \(\left(3^x\right)^2:3^3=\dfrac{1}{243}\)

\(\Leftrightarrow3^{2x}:3^3=\dfrac{1}{3^5}\)

\(\Leftrightarrow3^{2x}:3^3=3^{-5}\)

\(\Leftrightarrow3^{2x-3}=3^{-5}\)

\(\Leftrightarrow2x-3=-5\)

\(\Leftrightarrow2x=-5+3\)

\(\Leftrightarrow2x=-2\)

\(\Leftrightarrow x=-\dfrac{2}{2}\)

\(\Leftrightarrow x=1\)

Vậy \(x=1\)

c) \(2^{3x+2}=4^{x+5}\)

\(\Leftrightarrow2^{3x+2}=\left(2^2\right)^{x+5}\)

\(\Leftrightarrow2^{3x+2}=2^{2\left(x+5\right)}\)

\(\Leftrightarrow3x+2=2\left(x+5\right)\)

\(\Leftrightarrow3x+2=2x+10\)

\(\Leftrightarrow3x-2x=10-2\)

\(\Leftrightarrow x=8\)

Vậy \(x=8\)

d) \(3^{x+1}=9^x\)

\(\Leftrightarrow3^{x+1}=\left(3^2\right)^x\)

\(\Leftrightarrow3^{x+1}=3^{2x}\)

\(\Leftrightarrow x+1=2x\)

\(\Leftrightarrow2x-x=1\)

\(\Leftrightarrow x=1\)

Vậy \(x=1\)

Bạn ơi phần b sai đề rồi, phải là 27 chứ.

phần b nhé

(X+0,7)³=-27

(X+0,7)³=(-3)³

^X+0,7=-3

X=3-0,7=2,3

Vậy...