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

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