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

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

<gadget id="calculator">4 * 7</gadget>
<output>28</output>

<gadget id="calculator">28 + 3</gadget>
<output>31</output>

<result>31</result>