For numbers a and b, define the operation "△" as a△b=(a+3)*(b-5), then 6△7=how much.
对于数a，b定义运算"△"为a△b=(a+3)*(b-5)，那么6△7=多少．
<gadget id="calculator">6 + 3</gadget>
<output>9</output>

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

<gadget id="calculator">9 * 2</gadget>
<output>18</output>

<result>18</result>