What is the quotient of multiplying (7/9) by the largest single digit and dividing the product by the difference between (3/5) and (1/4)?
(7/9)乘最大的一位数，所得的积除以(3/5)与(1/4)的差，商是多少？
<gadget id="calculator">7 / 9</gadget>
<output>7/9 = around 0.777778</output>

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

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(3/5) - (1/4)</gadget>
<output>7/20 = around 0.35</output>

<gadget id="calculator">9 / (7/20)</gadget>
<output>180/7 = around 25.714286</output>

<gadget id="calculator">(7/9) * (180/7)</gadget>
<output>20</output>

<result>20</result>