Uncle Wang has some chickens and rabbits, and the number of chickens and rabbits is the same. These chickens and rabbits have a total of 84 legs. How many chickens does Uncle Wang keep? (solution by equation)
王大爷养有一些鸡和兔，鸡和兔的只数同样多．这些鸡和兔共有84条腿．王大爷养有鸡多少只？(用方程解)
<gadget id="calculator">2 + 4</gadget>
<output>6</output>

<gadget id="calculator">84 / 6</gadget>
<output>14</output>

<result>14</result>