1) \(7.4^x=7.4^3\Leftrightarrow4^x=4^3;x=3\)

2) \(\frac{3}{2.5^x}=\frac{3}{2.5^{12}}\Leftrightarrow5^x=5^{12};x=12\)

\(2^x=2.2^8=2^9;x=9\)

4) \(5.3^x=7.3^5-2.3^5\Leftrightarrow5.3^x=3^5.\left(7-2\right)\)

\(\Leftrightarrow3^5.x=3^5.5;x=5\)

3.3^x-2 + 5.3^x-2 -2.3³.3^x-2 =-414

(3+5-2.3³) . 3^x-2 =-414

-46. 3^x-2 = -414

3^x-2 = 9

x-2=2

x=4

1;Ta có\(5.3^x=5.3^4\)

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

\(\Rightarrow x=4\)

2.Ta có \(9.5^x=6.5^6+3.5^6\)

\(\Rightarrow9.5^x=5^6.\left(6+3\right)\)

\(\Rightarrow9.5^x=9.5^6\)

\(\Rightarrow5^x=5^6\)\

\(\Rightarrow x=6\)

3, Ta có \(2.3^{x+2}+4.3^{x+1}=10.3^6\)

\(\Rightarrow3^{x+1}.\left(2.3+4\right)=10.3^6\)

\(\Rightarrow3^{x+1}.10=10.3^6\)

\(\Rightarrow3^{x+1}=3^6\)

\(\Rightarrow x+1=6\)

\(\Rightarrow x=5\)

a) 5.3^x = 5.3⁴

=> 3^x=3⁴

=> x=4

b) 9.5^x=6.5⁶+3.5⁶

=> 9.5^x = (6+3)5⁶

=> 9.5^x=9.5⁶

=> 5^x=5⁶

=> x=6

c) 2.3^x+2 + 4.3^x+1 = 10.3⁶

=> 2.3^x+1.3 + 4.3^x+1 = 10.3⁶ 

=> 6.3^x+1+4.3^x+1=10.3⁶

=> (6+4).3^x+1=10.3⁶

=> 10.3^x+1=10.3⁶

=> 3^x+1=3⁶

=> x+1=6

=> x=5

`#3107`

b)

`2.3^x = 162`

`\Rightarrow 3^x = 162 \div 2`

`\Rightarrow 3^x = 81`

`\Rightarrow 3^x = 3^4`

`\Rightarrow x = 4`

Vậy, `x = 4`

c)

`(2x - 15)^5 = (2 - 15)^3`

\(\Rightarrow \)`(2x - 15)^5 - (2x - 15)^3 = 0`

\(\Rightarrow \)`(2x - 15)^3 . [ (2x - 15)^2 - 1] = 0`

\(\Rightarrow\left[{}\begin{matrix}\left(2x-15\right)^3=0\\\left(2x-15\right)^2-1=0\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}2x-15=0\\\left(2x-15\right)^2=1\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}2x=15\\\left(2x-15\right)^2=\left(\pm1\right)^2\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=\dfrac{15}{2}\\2x-15=1\\2x-15=-1\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=\dfrac{15}{2}\\2x=16\\2x=-14\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=\dfrac{15}{2}\\x=8\\x=-7\end{matrix}\right.\)

Vậy, `x \in`\(\left\{-7;8;\dfrac{15}{2}\right\}.\)

`d)`

\(3^{x+2}-5.3^x=?\) Bạn ghi tiếp đề nhé!

`e)`

\(7\cdot4^{x-1}+4^{x-1}=23?\)

\(4^{x-1}\cdot\left(7+1\right)=23\\ \Rightarrow4^{x-1}\cdot8=23\\ \Rightarrow4^{x-1}=\dfrac{23}{8}\)

Bạn xem lại đề!

`f)`

\(2\cdot2^{2x}+4^3\cdot4^x=1056\)

\(\Rightarrow2\cdot2^{2x}+\left(2^2\right)^3\cdot\left(2^2\right)^x=1056\\ \Rightarrow2\cdot2^{2x}+2^6\cdot2^{2x}=1056\\ \Rightarrow2^{2x}\cdot\left(2+2^6\right)=1056\\ \Rightarrow2^{2x}\cdot66=1056\\ \Rightarrow2^{2x}=1056\div66\\ \Rightarrow2^{2x}=16\\ \Rightarrow2^{2x}=2^4\\ \Rightarrow2x=4\\ \Rightarrow x=2\)

Vậy, `x = 2`

_____

\(10 -{[(x \div 3+17) \div 10+3.2^4] \div 10}=5\)

\(\Rightarrow\left[\left(x\div3+17\right)\div10+48\right]\div10=10-5\)

\(\Rightarrow\left[\left(x\div3+17\right)\div10+48\right]\div10=5\)

\(\Rightarrow\left(x\div3+17\right)\div10+48=50\)

\(\Rightarrow\left(x\div3+17\right)\div10=2\)

\(\Rightarrow x\div3+17=20\)

\(\Rightarrow x\div3=3\\ \Rightarrow x=9\)

Vậy, `x = 9.`

\(6^x+6+15^x+15^2=\)1377

\(6^x+15^x=1116\)

a) Ta có:

\(x=\frac{a-5}{a}=\frac{a}{a}-\frac{5}{a}=1-\frac{5}{a}\)

Để x nguyên thì \(\frac{5}{a}\)nguyên

=> 5 chia hết cho a

=> \(a\inƯ\left(5\right)\)

=> \(a\in\left\{1;-1;5;-5\right\}\)

b) 5.3^x+2 - 2.3^x-2 = 3627

=> 3^x-2.(5.3⁴ - 2.1) = 3627

=> 3^x-2.(5.81 - 2) = 3627

=> 3^x-2.(405 - 2) = 3627

=> 3^x-2.403 = 3627

=> 3^x-2 = 3627 : 403

=> 3^x-2 = 9 = 3²

=> x - 2 = 2

=> x = 2 + 2 = 4

a) 5.3²⁰²³ = 50.3²⁰²³ - 5.9ˣ

5.9ˣ = 50.3²⁰²³ - 5.3²⁰²³

5.(3²)ˣ = 5.3²⁰²³.(10 - 1)

5.(3²)ˣ = 5.3²⁰²³.9

3²ˣ = 3²⁰²³.3²

3²ˣ = 3²⁰²⁵

2x = 2025

x = 2025/2

b) 2.3ˣ + 5.3ˣ⁺¹ = 153

3ˣ.(2 + 5.3) = 153

3ˣ.17 = 153

3ˣ = 153/17

3ˣ = 9

3ˣ = 3²

x = 2