Question

Tìm x

x² - 7x = 0

Answer 1

`x^2 - 7x = 0`

`<=> x(x-7) = 0`

`<=>` \(\left[{}\begin{matrix}x=0\\x-7=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=0\\x=7\end{matrix}\right.\)

Vậy `x in {0;7}`

Answer 2

Help

 

Answer 3

x^2 - 7x = 0

<=> x ( x - 7 ) = 0

<=> x = 0 hoặc x = 7

Answer 4

\(x^2-7x=0\)

\(\Leftrightarrow x\left(x-7\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x-7=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=0\\x=7\end{matrix}\right.\)

Vậy \(x\in\left\{0;7\right\}\).

Answer 5

\(x^2-7=0\)

\(\Leftrightarrow x\left(x-7\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x\left(x-7\right)=0\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x=7\end{matrix}\right.\)

vậy x∈{0,7}