Question

[Ngọc Trâm]

2x + 1 = 5 Ở 2x+1 có dấu giá trị tuyệt đối nha giúp mình

Answer 1

[Nguyễn Huy Tú]

\(\left|2x+1\right|=5\)

\(\Rightarrow2x+1=\pm5\)

+) \(2x+1=5\Rightarrow2x=4\Rightarrow x=2\)

+) \(2x+1=-5\Rightarrow2x=-6\Rightarrow x=-3\)

Vậy \(x\in\left\{2;-3\right\}\)

Answer 2

[Trần Nguyễn Bảo Quyên]

\(\left|2x+1\right|=5\)

\(\Rightarrow\left[\begin{matrix}2x+1=5\\2x+1=-5\end{matrix}\right.\)

\(\Rightarrow\left[\begin{matrix}2x=5-1\\2x=-5-1\end{matrix}\right.\)

\(\Rightarrow\left[\begin{matrix}2x=4\\2x=-6\end{matrix}\right.\)

\(\Rightarrow\left[\begin{matrix}x=4:2\\x=-6:2\end{matrix}\right.\)

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

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