The difference between (4/5) minus (2/3) is (2/7) of a number, what is the number?
(4/5)减(2/3)的差是一个数的(2/7)，求这个数是多少？
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

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

<gadget id="calculator">(4/5) - (2/3)</gadget>
<output>2/15 = around 0.133333</output>

<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">(2/15) / (2/7)</gadget>
<output>7/15 = around 0.466667</output>

<result>7/15 = around 0.466667</result>