A {x € N} (x² +10x).(8x² – 7x +1)=0} B { -10; 0; 5; 1} Xác định : aUb, a giao b, b\a, a\b

\(\begin{array}{l}
\left( {{x^2} + 10x} \right)\left( {8{x^2} – 7x + 1} \right) = 0\\
\Leftrightarrow x\left( {x – 10} \right)\left( {8{x^2} – 7x + 1} \right) = 0\\
\Leftrightarrow \left[ \begin{array}{l}
x = 0\\
x = 10\\
x = \dfrac{{7 \pm \sqrt {17} }}{{16}}
\end{array} \right.\\
\Rightarrow A = \left\{ {0;10} \right\};B = \left\{ { – 10;0;5;1} \right\}\\
\Rightarrow A \cup B = \left\{ { – 10;0;5;1;10} \right\}\\
A \cap B = \left\{ 0 \right\}\\
A\backslash B = \left\{ {10} \right\};B\backslash A = \left\{ { – 10;5;1} \right\}
\end{array}\)