A project can be completed in 10 days if teams A and B work together. If team A works for 4 days and team B works for 6 days, the total (7/15) of the project will be completed. How many days will it take Team A to do this project alone?
一项工程，甲、乙两队合做，10天可以完成．如果甲队做4天，乙队做6天，共完成这项工程的(7/15)．求甲队独做这项工程要多少天？
<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">7 / 15</gadget>
<output>7/15 = around 0.466667</output>

<gadget id="calculator">(1/10) * 4</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(7/15) - (2/5)</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">6 - 4</gadget>
<output>2</output>

<gadget id="calculator">(1/15) / 2</gadget>
<output>1/30 = around 0.033333</output>

<gadget id="calculator">(1/10) - (1/30)</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">1 / (1/15)</gadget>
<output>15</output>

<result>15</result>