A Midea air conditioner is 1,800 yuan after a 30% discount. What is the original price of this air conditioner? (Only the column formula does not count)
一台美的空调打七折后是1800元，这台空调原价是多少？(只列式不计算)
<gadget id="calculator">70 / 100</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">1_800 / (7/10)</gadget>
<output>18_000/7 = around 2_571.428571</output>

<result>18_000/7 = around 2_571.428571</result>