If 25%x-4=2, then 75%x-2=how much.
若25%x-4=2，那么75%x-2=多少．
<gadget id="calculator">2 + 4</gadget>
<output>6</output>

<gadget id="calculator">6 * 3</gadget>
<output>18</output>

<gadget id="calculator">18 - 2</gadget>
<output>16</output>

<result>16</result>