If A*B means (A+2B)*(AB), then 7*5=how much.
若A*B表示(A+2B)*(A-B)，则7*5=多少．
<gadget id="calculator">2 * 5</gadget>
<output>10</output>

<gadget id="calculator">7 + 10</gadget>
<output>17</output>

<gadget id="calculator">7 - 5</gadget>
<output>2</output>

<gadget id="calculator">17 * 2</gadget>
<output>34</output>

<result>34</result>