There are a new batch of refrigerators in the commercial building, and the number of refrigerators that have been sold is 4 less than the total number (2/5). At this time, there are still 25 refrigerators left. How many have been sold?
商业大厦新进一批电冰箱，已卖了的比全部的(2/5)少4台，这时还剩25台，已卖了多少台？
<gadget id="calculator">25 - 4</gadget>
<output>21</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">21 / (3/5)</gadget>
<output>35</output>

<gadget id="calculator">35 * (2/5)</gadget>
<output>14</output>

<gadget id="calculator">14 - 4</gadget>
<output>10</output>

<result>10</result>