Define operation # as: A#B=A*B+(BA). Then 7#11=how much.
定义运算#为：A#B=A*B+(B-A)．那么7#11=多少．
<gadget id="calculator">7 * 11</gadget>
<output>77</output>

<gadget id="calculator">11 - 7</gadget>
<output>4</output>

<gadget id="calculator">77 + 4</gadget>
<output>81</output>

<result>81</result>