Bài 1:
\(a,\Leftrightarrow\left[{}\begin{matrix}x=3,6-1,2=2,4\\x=3,6+1,2=4,8\end{matrix}\right.\\ b,\Leftrightarrow\left|x-0,5\right|=2,5\Leftrightarrow\left[{}\begin{matrix}x=0,5+2,5=3\\x=0,5-2,5=-2\end{matrix}\right.\\ c,\Leftrightarrow\left\{{}\begin{matrix}x-2,8=0\\3,2-x=0\end{matrix}\right.\Leftrightarrow x\in\varnothing\)
Bài 2:
\(a,A=1,5-\left|x-4,5\right|\le1,5\\ A_{max}=1,5\Leftrightarrow x=4,5\\ b,B=-\left|2,9-x\right|-5\le-5\\ B_{max}=-5\Leftrightarrow x=2,9\)
Bài 3:
\(C=5+\left|x+1,3\right|\ge5\\ C_{min}=5\Leftrightarrow x=-1,3\)
b: \(\Leftrightarrow\left|x-0.5\right|=2.5\)
\(\Leftrightarrow\left[{}\begin{matrix}x=3\\x=-2\end{matrix}\right.\)