\(3x+17=12\\ 3x=12-17\\ 3x=\left(-5\right)\\ x=\dfrac{-5}{3}\)

\(\Leftrightarrow3^x=27\)

hay x=3

\(\Leftrightarrow3^x+3^x.3^2=270\Leftrightarrow3^x.10=270\\\Leftrightarrow3^x=3^3\Leftrightarrow x=3\)

\(3x^2+10x-8=0\\ \Leftrightarrow3x^2+12x-2x-8=0\\ \Leftrightarrow3x\left(x+4\right)-2\left(x+4\right)=0\\ \Leftrightarrow\left(x+4\right)\left(3x-2\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=-4\\x=\dfrac{2}{3}\end{matrix}\right.\)

Vậy \(x\in\left\{-4;\dfrac{2}{3}\right\}\)

     3x - 4 \(⋮\) 3 - x

\(\Rightarrow\) 3x - 4 + 3 . (3 - x) \(⋮\) 3 - x

\(\Rightarrow\) 5 \(⋮\) 3 - x

\(\Rightarrow\) 3 - x \(\in\) Ư(5) = {1 ; - 1 ; 5 ; - 5}

\(\Rightarrow\) x \(\in\) {2 ; 4 ; - 2 ; 8}

=3x^2-15x-3x^2+7x

=-15x+7x

=-8x

sai đề bài

sai de roi

sai roi lam j tinh duoc

x=\(\frac{4\ln3}{5\ln2}\)

x = 1,27

thì 32^x \(\approx\) 81,5

Tìm x:

a. 81 – x = 27

   X = 81 - 27= 54

b. 4 x X = 32

   X =32 : 4=8

2.(1 + 3 + 3² + ... + 3ˣ) + 1 = 81

2.(3ˣ⁺¹ - 1)/2 + 1 = 81

3ˣ⁺¹ - 1 + 1 = 81

3ˣ⁺¹ = 81 

3ˣ⁺¹ = 3⁴

x + 1 = 4

x = 4 - 1

x = 3