Question

\(\sqrt{3x-1}\)=4

Answer 1

ĐKXĐ: 3x - 1 \(\ge0\Leftrightarrow3x\ge1\Leftrightarrow x\ge\dfrac{1}{3}\)

\(\sqrt{3x-1}=4\\ \Leftrightarrow\left|3x-1\right|=16\\ \Leftrightarrow\left[{}\begin{matrix}3x-1=16\\3x-1=-16\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}3x=17\\3x=-15\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}x=\dfrac{17}{3}\left(tm\right)\\x=-5\left(ktm\right)\end{matrix}\right.\)

Vậy x = 17/3

Answer 2

=>3x-1=16

=>3x=17

=>x=17/3