Đáp án:
Giải thích các bước giải:
$\begin{array}{l}
\left| x \right| = 3 \to \left[ \begin{array}{l}
x = - 3\\
x = 3
\end{array} \right.\\
\to \left[ \begin{array}{l}
A = 4.{\left( { - 3} \right)^2} - 5.{\left( { - 3} \right)^3} - \left( { - 3} \right) + 3 = 177\\
A = 4.{\left( 3 \right)^2} - 5.{\left( 3 \right)^3} - \left( 3 \right) + 3 = - 99
\end{array} \right.\\
a.\left( {x + 3} \right) \in U\left( { - 10} \right)\\
\to \left[ \begin{array}{l}
x + 3 = - 10\\
x + 3 = 10\\
x + 3 = 5\\
x + 3 = - 5\\
x + 3 = 1\\
x + 3 = - 1
\end{array} \right. \to \left[ \begin{array}{l}
x = - 13\\
x = 7\\
x = 2\\
x = - 8\\
x = - 2\\
x = - 4
\end{array} \right.\\
b.\left( {x - 9} \right) \vdots \left( {x - 7} \right) \to 2 \vdots \left( {x - 7} \right)\\
\to \left( {x - 7} \right) \in U\left( 2 \right)\\
\to \left[ \begin{array}{l}
x - 7 = 2\\
x - 7 = - 2\\
x - 7 = 1\\
x - 7 = - 1
\end{array} \right. \to \left[ \begin{array}{l}
x = 9\\
x = 5\\
x = 8\\
x = 6
\end{array} \right.\\
a.\left( {x - 3} \right)\left( {y - 5} \right) = 7\\
\to \left[ \begin{array}{l}
\left\{ \begin{array}{l}
x - 3 = 1\\
y - 5 = 7
\end{array} \right.\\
\left\{ \begin{array}{l}
x - 3 = 7\\
y - 5 = 1
\end{array} \right.
\end{array} \right. \to \left[ \begin{array}{l}
\left\{ \begin{array}{l}
x = 4\\
y = 12
\end{array} \right.\\
\left\{ \begin{array}{l}
x = 10\\
y = 6
\end{array} \right.
\end{array} \right.\\
b.\left( {x - 1} \right)\left( {xy - 5} \right) = 5\\
\to \left[ \begin{array}{l}
\left\{ \begin{array}{l}
x - 1 = 5\\
xy - 5 = 1
\end{array} \right.\\
\left\{ \begin{array}{l}
x - 1 = 1\\
xy - 5 = 5
\end{array} \right.
\end{array} \right. \to \left[ \begin{array}{l}
\left\{ \begin{array}{l}
x = 6\\
y = 1
\end{array} \right.\\
\left\{ \begin{array}{l}
x = 2\\
y = 5
\end{array} \right.
\end{array} \right.
\end{array}$
