Use "△" to represent an operation symbol, and its meaning is a△b=((ab)/(ab)), then 5△3=how much.
用"△"表示一种运算符号，其含义是a△b=((ab)/(a-b))，则5△3=多少．
<gadget id="calculator">5 * 3</gadget>
<output>15</output>

<gadget id="calculator">5 - 3</gadget>
<output>2</output>

<gadget id="calculator">15 / 2</gadget>
<output>15/2 = around 7.5</output>

<result>15/2 = around 7.5</result>