Question

Tìm x biết : (x+2)/2=8/(x+2)

Answer 1

ĐK: \(x \ne -2\)

\(\dfrac{x+2}{2}=\dfrac{8}{x+2} \\ \Leftrightarrow (x+2)^2=8.2 \\ \Leftrightarrow (x+2)^2=4^2=(-4)^2 \\ \Leftrightarrow\left[ \begin{array}{l}x+2=4\\x+2=-4\end{array} \right. \\ \Leftrightarrow \left[ \begin{array}{l}x=2\\x=-6\end{array} \right. \)

Vậy \(x=2;x=-6\).

Answer 2

Giúp mik vs mik đang cần gấp

Answer 3

cái....đánh máy xong công thức xong rồi đến lúc chèn vào nó lỗi, cáu:vv

\(\dfrac{x+2}{2}=\dfrac{8}{x+2}\Rightarrow\left(x+2\right)^2=16\)

\(\Rightarrow\left[{}\begin{matrix}\left(x+2\right)^2=4^2\\\left(x+2\right)^2=\left(-4\right)^2\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x+2=4\\x+2=-4\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=2\\x=-6\end{matrix}\right.\)

Vậy...

Answer 4

ĐKXĐ: x≠-2

Ta có: \(\dfrac{x+2}{2}=\dfrac{8}{x+2}\)

\(\Leftrightarrow\left(x+2\right)^2=16\)

\(\Leftrightarrow\left[{}\begin{matrix}x+2=4\\x+2=-4\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=2\left(nhận\right)\\x=-6\left(nhận\right)\end{matrix}\right.\)

Vậy: \(x\in\left\{2;-6\right\}\)

Answer 5

x=2

Answer 6

x²+2²=2.8

x²+4=16

x²=16-4

x²=12

vay x bang +_{_ can 12}