If 6x-20=10, then 10x-8.5=how much.
如果6x-20=10，那么10x-8.5=多少．
<gadget id="calculator">10 + 20</gadget>
<output>30</output>

<gadget id="calculator">30 / 6</gadget>
<output>5</output>

<gadget id="calculator">10 * 5</gadget>
<output>50</output>

<gadget id="calculator">50 - 8.5</gadget>
<output>41.5</output>

<result>41.5</result>