Question

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3-2 (x - 1 ) ^2=2,5

(4x^2 - 1).( 27x^3 + 8)= 0

Answer 1

đề bài là gì?

Answer 2

Đề bài : tìm x,  biết 

Answer 3

^ nghĩa là sao ?dấu này nghĩa?  là gì

Answer 4

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

\(\Leftrightarrow3-2\left(x-1\right)^2=\dfrac{5}{2}\)

\(\Rightarrow2\left(x-1\right)^2=3-\dfrac{5}{2}=\dfrac{1}{2}\)

\(\Rightarrow\left(x-1\right)^2=\dfrac{1}{2}:2=\dfrac{1}{4}\)

\(\Rightarrow x-1=\dfrac{1}{4}:x-\dfrac{1}{4}\Leftrightarrow2x-1=0\Rightarrow2x=1\Rightarrow x=\dfrac{1}{2}\)

Answer 5

\(\left(4x^2-1\right)\left(27x^3+8\right)=0\)

\(\Rightarrow\left[{}\begin{matrix}4x^2-1=0\\27x^3+8=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}4x^2=1\\27x^3=-8\end{matrix}\right.\Rightarrow}\left[{}\begin{matrix}x^2=\dfrac{1}{4}\\x^3=\dfrac{-8}{27}\end{matrix}\right.\Rightarrow}x=\dfrac{1}{2}}\)

Answer 6

3-2(x-1)²=2,5

   2(x-1)²=3-\(\dfrac{5}{2}\) 

   2(x-1)²=\(\dfrac{1}{2}\) 

      (x-1)²=\(\dfrac{1}{2}:2\) 

      (x-1)²=\(\dfrac{1}{4}\) 

⇒(x-1)²=\(\left(\dfrac{1}{4}\right)^2\) hoặc (x-1)²=\(\left(\dfrac{-1}{4}\right)^2\) 

    x-1=\(\dfrac{1}{4}\) hoặc x-1=\(\dfrac{-1}{4}\) 

       x=\(\dfrac{5}{4}\) hoặc x=\(\dfrac{3}{4}\)

Answer 7

(4x²-1).(27.x³+8)=0

⇒4x²-1=0 hoặc 27.x³+8=0

          x=\(\dfrac{1}{2}\) hoặc x=\(\dfrac{-1}{2}\) hoặc x=\(\dfrac{-2}{3}\)