It takes 6 hours for A, B, and C to complete a job together. If A works for 6 hours and B and C cooperate for 2 hours, the work can be completed (2/3); if A and B cooperate for 3 hours, C can complete the work for 6 hours (2/3). If A and B cooperate, how many hours will it take to complete the work?
一项工作，甲乙丙三人合作要6小时完成．如果甲工作6小时后，乙丙合作2小时，可完成这项工作的(2/3)；如果甲乙合作3小时后，丙做6小时，也可完成这项工作的(2/3)．如果甲乙合作需要几小时完成这项工作？
<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">(1/6) * 3</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(2/3) - (1/2)</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">6 - 3</gadget>
<output>3</output>

<gadget id="calculator">(1/6) / 3</gadget>
<output>1/18 = around 0.055556</output>

<gadget id="calculator">(1/6) - (1/18)</gadget>
<output>1/9 = around 0.111111</output>

<gadget id="calculator">1 / (1/9)</gadget>
<output>9</output>

<result>9</result>