A =\(\left\{x\in N\backslash\left(2x-x^2\right)\left(2x^2-3x-2\right)=0\right\}\)
B =\(\left\{n\in N^+\backslash3x< n< 30\right\}\)
Xét A
\(\left(2x-x^2\right)\left(2x^2-3x-2\right)=0\)
=> \(\left[{}\begin{matrix}\left(2x-x^2\right)=0=>x=2;x=0\\\\\left(2x^2-3x-2\right)=0=>x=2;x=-\frac{1}{2}\end{matrix}\right.\)
Vì \(x\in N\) => \(A=\left\{2\right\}\)
Xét B
\(3x< n^2< 30\)
<=> \(6< n^2< 30\)
<=> \(\sqrt{6}< n< \sqrt{30}\)
=>\(\left[\sqrt{6};\sqrt{30}\right]\)
Vì \(B\in N^+\) => \(B=\left[3;5\right]\)
\(A\cap B=\varnothing\)
