Question

tìm x biết

a) /3x+1/ -17=-12

b) 2x + /x-2/ =7

c) /3-2x/=x+1

Answer 1

Biết làm câu a thôi, thông cảm

a) \(\left|3x+1\right|-17=-12\\ \left|3x+1\right|=-12+17\\ \left|3x+1\right|=5\\ \Rightarrow\left[{}\begin{matrix}3x+1=5\\3x+1=-5\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}3x=5-1\\3x=-5-1\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}3x=4\\3x=-6\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=4:3\\x=\left(-6\right):3\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=\frac{4}{3}\\x=-2\end{matrix}\right.\)Vậy \(x\in\left\{\frac{4}{3};-2\right\}\)