Let p and q be two numbers, stipulate: p△q=3*p-(p+q)/2, find 7△(2△4)
设p、q是两个数，规定：p△q=3*p-(p+q)/2，求7△(2△4)
<gadget id="calculator">3 * 2</gadget>
<output>6</output>

<gadget id="calculator">2 + 4</gadget>
<output>6</output>

<gadget id="calculator">6 / 2</gadget>
<output>3</output>

<gadget id="calculator">6 - 3</gadget>
<output>3</output>

<gadget id="calculator">3 * 7</gadget>
<output>21</output>

<gadget id="calculator">7 + 3</gadget>
<output>10</output>

<gadget id="calculator">10 / 2</gadget>
<output>5</output>

<gadget id="calculator">21 - 5</gadget>
<output>16</output>

<result>16</result>