Question

tìm x thuộc z,biết

|2x-6|=3-x

mik cần gấp

Answer 1

\(\left|2x-6\right|=3-x\)

\(\Rightarrow\left[{}\begin{matrix}2x-6=3-x\\2x-6=-\left(3-x\right)\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}2x-6=3-x\\2x-6=-3+x\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}2x+x=3+6\\2x-x=-3+6\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}3x=9\\x=3\end{matrix}\right.\)

\(\Rightarrow x=3\)

Answer 2

\(|2x-6|=x-3\left(x\ge3\right)\)

\(\Rightarrow\left[{}\begin{matrix}2x-6=x-3\\2x-6=-x+3\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}2x-x=-3+6\\2x+x=3+6\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=3\\3x=9\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=3\\x=3\end{matrix}\right.\)

Vậy: x=3

Answer 3

\(\Leftrightarrow\left\{{}\begin{matrix}x< =3\\\left(2x-6-3+x\right)\left(2x-6+3-x\right)=0\end{matrix}\right.\)

\(\Leftrightarrow\left\{{}\begin{matrix}x< =3\\\left(3x-9\right)\left(x-3\right)=0\end{matrix}\right.\Leftrightarrow x=3\)