If a△b=((ab)/(a+b)), then 5△8=((())/(())).
如果a△b=((ab)/(a+b))，那么5△8=((())/(()))．
<gadget id="calculator">5 * 8</gadget>
<output>40</output>

<gadget id="calculator">5 + 8</gadget>
<output>13</output>

<gadget id="calculator">40 / 13</gadget>
<output>40/13 = around 3.076923</output>

<result>40/13 = around 3.076923</result>