Suppose A*B means 3 times of A minus 2 times of B, that is, A*B=3A-2B. It is known that X※(4※1)=7, then X※4=how much.
假设A※B表示A的3倍减去B的2倍，即A※B=3A-2B．己知X※(4※1)=7，那么X※4=多少．
<gadget id="calculator">9 * 3</gadget>
<output>27</output>

<gadget id="calculator">2 * 4</gadget>
<output>8</output>

<gadget id="calculator">27 - 8</gadget>
<output>19</output>

<result>19</result>