The TV factory produced 8,400 color TV sets last year, an increase of (1/5) compared with the previous year. How many color TV sets were produced in the previous year?
电视机厂去年生产彩电8400台，比前年增产了(1/5)，前年生产彩电多少台？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 + (1/5)</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">8_400 / (6/5)</gadget>
<output>7_000</output>

<result>7_000</result>