According to 4x+7=39, what is the difference of 3x-6?
根据4x+7=39，可以得出3x-6的差是多少
<gadget id="calculator">39 - 7</gadget>
<output>32</output>

<gadget id="calculator">32 / 4</gadget>
<output>8</output>

<gadget id="calculator">3 * 8</gadget>
<output>24</output>

<gadget id="calculator">24 - 6</gadget>
<output>18</output>

<result>18</result>