Assuming that a and b represent arbitrary integers, the operation of "*" is stipulated as follows: a*b=(a+b)*(ab), then 68*18=how much.
假设a、b表示任意整数，规定"*"的运算如下：a*b=(a+b)*(a-b)则68*18=多少．
<gadget id="calculator">68 + 18</gadget>
<output>86</output>

<gadget id="calculator">68 - 18</gadget>
<output>50</output>

<gadget id="calculator">86 * 50</gadget>
<output>4_300</output>

<result>4_300</result>