Define "A☆B" as 3 times of A minus 2 times of B, that is, A☆B=3A-2B, given that x☆(4☆1)=7, then x=how much.
定义"A☆B"为A的3倍减去B的2倍，即A☆B=3A-2B，已知x☆(4☆1)=7，则x=多少．
<gadget id="calculator">4 * 3</gadget>
<output>12</output>

<gadget id="calculator">1 * 2</gadget>
<output>2</output>

<gadget id="calculator">12 - 2</gadget>
<output>10</output>

<gadget id="calculator">10 * 2</gadget>
<output>20</output>

<gadget id="calculator">7 + 20</gadget>
<output>27</output>

<gadget id="calculator">27 / 3</gadget>
<output>9</output>

<result>9</result>