Question

Giải phương trình:

|4x|=|x+30|

Answer 1

\(\Leftrightarrow\left\{{}\begin{matrix}4x=x+30\\4x=-x-30\end{matrix}\right.\)

\(\Leftrightarrow\left\{{}\begin{matrix}3x=30\\5x=-30\end{matrix}\right.\)

\(\Leftrightarrow\left\{{}\begin{matrix}x=10\\x=-6\end{matrix}\right.\)

Vậy S=...

Answer 2

|4x|=|x+30|

<=>4x=x+30

<=>4x-x=30

<=>3x=30

<=>x=10

Answer 3

|4x|=|x+30|

<=>4x=-x-30

<=>4x+x=-30

<=>5x=-30

<=>x=6