- $ A = \\\emptyset ,{\\\text{ }}B = \\\left\\\{ {x \\\in \\\mathbb{R}\\\left| {{x^2} + x + 1 = 0} \\\right.} \\\right\\\}$.
- $ A = \\\{ 1;3\\\} ,{\\\text{ }}B = \\\left\\\{ {x \\\in \\\mathbb{R}\\\left| {\\\left( {x-1} \\\right)\\\left( {x - 3} \\\right){\\\text{ = }}0} \\\right.} \\\right\\\}$.
- $ A = \\\{ 1;3;5;7;9\\\} ,\\\,\\\,B = \\\left\\\{ {n \\\in \\\mathbb{N}\\\left| {n = 2k + 1,{\\\text{ }}k \\\in \\\mathbb{Z},0 \\\leqslant k \\\leqslant 4} \\\right.} \\\right\\\}$.
- $ A = \\\{ - 1;2\\\} ,{\\\text{ }}B = \\\left\\\{ {x \\\in \\\mathbb{R}\\\left| {{x^2} - 2x - 3 = 0} \\\right.} \\\right\\\}$.