For a telephone line, (3/4) meters are used for the first time, and the remaining (3/4) is used for the second time, and 6 meters are used for the two times. How much rice is left after the first use?
一根电话线，第一次用去(3/4)米，第二次用去余下的(3/4)，两次共用去6米．第一次用去后还剩下多少米？
<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">6 - (3/4)</gadget>
<output>21/4 = around 5.25</output>

<gadget id="calculator">(21/4) / (3/4)</gadget>
<output>7</output>

<result>7</result>