It is known that 2x+40=56, then 4x+20=how much.
已知2x+40=56，那么4x+20=多少．
<gadget id="calculator">56 - 40</gadget>
<output>16</output>

<gadget id="calculator">16 / 2</gadget>
<output>8</output>

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

<gadget id="calculator">32 + 20</gadget>
<output>52</output>

<result>52</result>