If 3x+4=25, then, 9.5x-16.5=how much.
如果3x+4=25，那么，9.5x-16.5=多少．
<gadget id="calculator">25 - 4</gadget>
<output>21</output>

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

<gadget id="calculator">9.5 * 7</gadget>
<output>66.5</output>

<gadget id="calculator">66.5 - 16.5</gadget>
<output>50</output>

<result>50</result>