Question

Tìm x, biết:

|2x - 1| + 7x = 1

Answer 1

Ta có: \(\left|2x-1\right|+7x=1\)

\(\Leftrightarrow\left|2x-1\right|=1-7x\)

\(\Leftrightarrow\left[{}\begin{matrix}2x-1=1-7x\left(x\ge\dfrac{1}{2}\right)\\2x-1=7x-1\left(x< \dfrac{1}{2}\right)\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}9x=2\\x=0\left(nhận\right)\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{2}{9}\left(loại\right)\\x=0\left(nhận\right)\end{matrix}\right.\)