\(3^{x+2}-3^x\cdot2^3=27\\\Rightarrow 3^x\cdot3^2-3^x\cdot8=27\\\Rightarrow 3^x\cdot(3^2-8)=27\\\Rightarrow 3^x\cdot(9-8)=3^3\\\Rightarrow 3^x=3^3\\\Rightarrow x=3\)

\(=3^x\cdot3+2x\cdot3^x-9\left(2x+3\right)\)

=3^x(2x+3)-9(2x+3)

=(2x+3)(3^x-9)

Đề như thế này phải ko ạ??

\(2\sqrt{3x}-4\sqrt{3x}+27-3\sqrt{3x}.\)

ĐKXĐ : \(x\ge0\)

\(=2\sqrt{3x}-4\sqrt{3x}-3\sqrt{3x}+27\)

\(=\sqrt{3x}\left(2-4-3\right)+27\)

\(=-5\sqrt{3x}+27\)

\(\Rightarrow-5\sqrt{3x}=-27\)

\(\Rightarrow\sqrt{3x}=\frac{27}{5}\)

\(\Rightarrow\sqrt{3x}=\sqrt{\frac{729}{25}}\)

\(\Rightarrow3x=\frac{729}{25}\)

\(\Rightarrow x=\frac{243}{25}=9,72\)

ý :v sai ngu rồi :vvv Sorry bạn :> Mik xin được làm lại

\(2\sqrt{3x}-4\sqrt{3x}+27-3\sqrt{3x}\)

ĐKXĐ\(x\ge0\)

\(=2\sqrt{3x}-4\sqrt{3x}-3\sqrt{3x}+27\)

\(=\sqrt{3x}\left(2-4-3\right)+27\)

\(=-5\sqrt{3x}+27\)

bài dưới chỉ đúng với trường hợp phép tính trên bằng 0 thoi ạ >: mà đề ko có >: Thực lòng xin lỗi ạ

Tìn x ạ?

-1 5/27-(3x-7/9)3=-24/27

 (3x-7/9)3 =-32/27-(-24/27)

 (3x-7/9)3=-8/27 

(3x-7/9)3=(-2/3)3

⇒3x-7/9=-2/3

  3x =-2/3+7/9

 3x =1/9

x =1/9:3

x =1/27

Chúc bạn học tốt!

  \(\left(\frac{x^2+3x}{x^3+3x^2+9x+27}\right)\): \(\left(\frac{1}{x-3}-\frac{6x}{x^3-3x^2+9x-27}\right)\)

=\(\left[\frac{x\left(x+3\right)}{x^2\left(x+3\right)+9\left(x+3\right)}\right]\):\(\left[\frac{1}{x-3}-\frac{6x}{x^2\left(x-3\right)+9\left(x-3\right)}\right]\)

=\(\left[\frac{x\left(x-3\right)}{\left(x^2+9\right)\left(x-3\right)}\right]\):\(\left[\frac{1}{x-3}-\frac{6x}{\left(x^2+9\right)\left(x-3\right)}\right]\)

=\(\frac{x}{x^2+9}\):\(\left[\frac{x^2+9}{\left(x-3\right)\left(x^2+9\right)}-\frac{6x}{\left(x-3\right)\left(x^2+9\right)}\right]\)

=\(\frac{x}{x^2+9}\):\(\frac{\left(x-3\right)^2}{\left(x-3\right)\left(x^2+9\right)}\)

=\(\frac{x}{x^2+9}\):\(\frac{x-3}{x^2+9}\)

=\(\frac{x}{x^2+9}\).\(\frac{x^2+9}{x-3}\)

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

nguyen ngoc anh:

\(\frac{3x}{27}=27\)

\(\Rightarrow3x:27=27\)

\(\Rightarrow3x=27\times27\)

\(\Rightarrow3x=729\)

\(x=729:3\)

\(x=243\)

Vậy\(x=27\)

Tham khảo nha!

\(\frac{3x}{27}=27\)<=> 3x=729<=> x=243

Sorry: \(x=243\)nhé!

a. Kiểm tra lại mẫu số vế phải, \(7-5x\) hay \(7-3x\) 

b. ĐKXĐ: \(x\ne-\dfrac{5}{3}\)

\(\dfrac{3x+5}{12}=\dfrac{3}{5+3x}\)

\(\Leftrightarrow\dfrac{\left(3x+5\right)^2}{12\left(3x+5\right)}=\dfrac{36}{12\left(3x+5\right)}\)

\(\Rightarrow\left(3x+5\right)^2=36=6^2\)

\(\Rightarrow\left[{}\begin{matrix}3x+5=6\\3x+5=-6\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=\dfrac{1}{3}\\x=-\dfrac{11}{3}\end{matrix}\right.\) (thỏa mãn)