Bài 1:
a) \(\Leftrightarrow A=x^3-8-x^3-2x=-2x-8\)
b) \(\left|x-1\right|=3\\ \Leftrightarrow\left[{}\begin{matrix}x-1=-3\\x-1=3\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}x=-2\\x=4\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}A=-2.-2-8=-4\\A=-2.4-8=-16\end{matrix}\right.\)
\(a,A=x^3+8-x^3-2x=8-2x\\ b,\left|x-1\right|=3\Leftrightarrow\left[{}\begin{matrix}x-1=3\\1-x=3\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=4\\x=-2\end{matrix}\right.\\ \forall x=4\Leftrightarrow A=8-2\cdot4=0\\ \forall x=-2\Leftrightarrow A=8-2\left(-2\right)=12\)
