If the sum of a number and itself is 8.6, what is the product of these two numbers?
一个数与它自己相加为8.6，那么这两个数相乘积是多少．
<gadget id="calculator">8.6 / 2</gadget>
<output>4.3</output>

<gadget id="calculator">4.3 * 4.3</gadget>
<output>18.49</output>

<result>18.49</result>