What is the sum of (4/5) and (5/8) multiplied by their difference?
(4/5)与(5/8)的和乘它们的差，结果是多少？
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">5 / 8</gadget>
<output>5/8 = around 0.625</output>

<gadget id="calculator">(4/5) + (5/8)</gadget>
<output>57/40 = around 1.425</output>

<gadget id="calculator">(4/5) - (5/8)</gadget>
<output>7/40 = around 0.175</output>

<gadget id="calculator">(57/40) * (7/40)</gadget>
<output>399/1_600 = around 0.249375</output>

<result>399/1_600 = around 0.249375</result>