Subtract the quotient of 2.5 divided by 5 from twice x, the difference is 38, find x.
x的2倍减去2.5除5的商，差得38，求x．
<gadget id="calculator">5 / 2.5</gadget>
<output>2</output>

<gadget id="calculator">2 + 38</gadget>
<output>40</output>

<gadget id="calculator">40 / 2</gadget>
<output>20</output>

<result>20</result>