It is stipulated that a*b=(b+a)*b, then 3*5=how much.
规定a*b=(b+a)*b，则3*5=多少．
<gadget id="calculator">3 + 5</gadget>
<output>8</output>

<gadget id="calculator">8 * 5</gadget>
<output>40</output>

<result>40</result>