a) \(x\ge5\Rightarrow\left\{{}\begin{matrix}x-5\ge0\\3-x\le0\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}\left|x-5\right|=x-5\\\left|3-x\right|=-\left(3-x\right)=x-3\end{matrix}\right.\)
\(pt\Leftrightarrow x-5+x-3-3=15\)
\(\Leftrightarrow2x-11=15\)
\(\Leftrightarrow2x=26\)
\(\Leftrightarrow x=13\left(tm\right)\)
b) \(\)\(-5\le x\le\dfrac{3}{2}\)
\(\Rightarrow\left\{{}\begin{matrix}2x-3\le0\\x+5\ge0\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}\left|2x-3\right|=3-2x\\\left|x+5\right|=x+5\end{matrix}\right.\)
\(pt\Leftrightarrow3-2x+x+5=3\)
\(\Leftrightarrow x=5\left(ktm\right)\)
\(\Leftrightarrow x\in\varnothing\)
Đúng 2
Bình luận (0)