For a piece of iron, (9/10) meters are used as material for the first time, and the remaining (3/5) is used as a small door for the second time, and 6 meters are shared between the two times. How long is this piece of iron originally?
一块铁片，第一次用去(9/10)米做材料，第二次用去余下的(3/5)做小门，两次共用去6米．这块铁片原来长多少米？
<gadget id="calculator">9 / 10</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">6 - (9/10)</gadget>
<output>51/10 = around 5.1</output>

<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">(51/10) / (3/5)</gadget>
<output>17/2 = around 8.5</output>

<gadget id="calculator">(17/2) + (9/10)</gadget>
<output>47/5 = around 9.4</output>

<result>47/5 = around 9.4</result>