3^x+3^x+1+3^x+2=243.39

 3^x+3^x.3+3^x.9=9477

     3^x.(1+3+9)=9477

              3^x.13=9477

                   3^x=729=3⁶

                          x=6

3^x + 3^x+1 + 3^x+2 = 243.39

<=> 3^x + 3^x.3 + 3^x.3² = 243.39

<=> 3^x( 1 + 3 + 3² ) = 243.39

<=> 3^x.13 = 243.39

<=> 3^x = 243.3 = 729

<=> 3^x = 3⁶

<=> x = 6

Bài 1

12³.3²

=(2.6)³.3²

=2³.6³.3²

=2³.2³.3⁵

=2³⁺³.3⁵

=2⁶.3⁵

Bài 2:Tìm X

(x-2)⁵=243

(x-2)⁵=3⁵

=>(x-2)=3

     x    =3+2

     x    =5

    2^x+2^x+4=272

    2^x+2^x+4=2⁴+2⁸

=>     x     =4

=12.12.12.3.3=3.4.3.4.3.4.3.3=3.3.3.3.3.4.4.4=3 mũ 5 . 4 mũ 3

Giải:

a) câu này mình bó tay, chắc sai đề. không có số nào mũ 3 = 243.

b) 3² x 3^x = 81

=> 3^2+x=81

=> 3^2+x=3⁴

=> 2 + x = 4 => x = 2

c) (2x + 1)⁴=16

=> (2x + 1)⁴=2⁴

=> 2x + 1 = 2

=> không có x nào để thỏa mãn (2x + 1)⁴=16.

d) x²⁰=x => x = {0;1}

a, x^3 = 243

=> x^3 = 7^3

=> x = 7

b, 3^2 . 3^x = 81

=> 3^2x = 3^4

=> 2x =4

=> x = 4

c, (2x + 1)^4 = 16

=> (2x + 1) ^4 = 2^4 = (-2)^4

TH1 : 2x + 1 = 2 

=> 2x = 1

=> x = 1/2

TH2 : 2x + 1 = -2

=> 2x = -3

=> x = -3/2

d, x^20 = x

=> x = 0 hoặc 1

3^x . 3^x+1 = 243

<=> 3^x+x+1 = 3⁵

<=> 2x+1 = 5

<=> x = 2

3^x x 3^x+1 = 243

3^x x 3^x+1 = 3⁵

=> X x X+1=5

=> x²         = 5+1

=> x²         = 6

=> x=6

Vậy x = 6

# Chúc bạn học tốt #

  Bài 1:

2^\(x\) = 4

2\(^x\) = 2²

 \(x=2\)

Vậy \(x=2\)

Bài 2:

2\(^x\) = 8

2\(^x\) = 2³

\(x=3\)

Vậy \(x=3\)

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

\(\Rightarrow3^{2x+1}=3^5\)

\(\Rightarrow2x+1=5\)

\(\Rightarrow2x=5-1\)

\(\Rightarrow2x=4\)

\(\Rightarrow x=4:2\)

\(\Rightarrow x=2\)

\(3^2x+1=243\)

\(9x=243-1\)

\(9x=242\)

\(x=242:9\)

\(\Rightarrow x=\dfrac{242}{9}\)

a) \(5\left(x+7\right)-10=2^3\cdot5\)

\(\Rightarrow5\left(x+7\right)-10=40\)

\(\Rightarrow5\left(x+7\right)=40+10\)

\(\Rightarrow x+7=\dfrac{50}{5}\)

\(\Rightarrow x+7=10\)

\(\Rightarrow x=10-7\)

\(\Rightarrow x=3\)

b) \(9x-2\cdot3^2=3^4\)

\(\Rightarrow9x-18=81\)

\(\Rightarrow9x=81+18\)

\(\Rightarrow9x=99\)

\(\Rightarrow x=\dfrac{99}{9}\)

\(\Rightarrow x=11\)

c) \(5^{25}\cdot5^{x-1}=5^{25}\)

\(\Rightarrow5^{x-1}=5^{25}:5^{25}\)

\(\Rightarrow5^{x-1}=1\)

\(\Rightarrow5^{x-1}=5^0\)

\(\Rightarrow x-1=0\)

\(\Rightarrow x=1\)

a) $5\left(x+7\right)-10=2^3\cdot 5$

$\Rightarrow 5\left(x+7\right)-10=40$

$\Rightarrow 5\left(x+7\right)=40+10$

$\Rightarrow x+7=\genfrac{}{}{0ex}{}{50}{5}$

$\Rightarrow x+7=10$

$\Rightarrow x=10-7$

$\Rightarrow x=3$

b) $9x-2\cdot 3^2=3^4$

$\Rightarrow 9x-18=81$

$\Rightarrow 9x=81+18$

$\Rightarrow 9x=99$

$\Rightarrow x=\genfrac{}{}{0ex}{}{99}{9}$

$\Rightarrow x=11$

c) $5^{25}\cdot 5^{x-1}=5^{25}$

$\Rightarrow 5^{x-1}=5^{25}:5^{25}$

$\Rightarrow 5^{x-1}=1$

$\Rightarrow 5^{x-1}=5^0$

$\Rightarrow x-1=0$

$\Rightarrow x=1$

2^x = 64

⇒ 2^x = 2⁶

⇒ x = 6.

7^x = 7¹⁰ : 7⁵

⇒ 7^x = 7⁵

⇒ x = 5.

3^x = 3¹⁵ : 243

⇒ 3^x = 3¹⁵ : 3⁵

⇒ 3^x = 3¹⁰

⇒ x = 10.

\(2^x=64=2^6\Rightarrow x=6\\ ---\\ 7^x=7^{10}:7^5=7^5\Rightarrow x=5\\ ----\\ 3^x=3^{15}:243=3^{15}:3^5=3^{10}\Rightarrow x=10\)