A shopping mall sells a batch of commodities at a reduced price during the exhibition period. If you sell it at a 10% discount, you can make a profit of 2,150 yuan; if you sell it at a 20 percent discount, you will lose 1,250 yuan. Q: How much is the purchase price of this batch of goods?
某商场在展销期间，将一批商品降价出售．如果打九折出售，可盈利2150元；如果打八折出售，会亏损1250元．问：这批商品的购入价是多少元？
<gadget id="calculator">2_150 + 1_250</gadget>
<output>3_400</output>

<gadget id="calculator">90 / 100</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">(9/10) - (4/5)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">3_400 / (1/10)</gadget>
<output>34_000</output>

<gadget id="calculator">34_000 * (4/5)</gadget>
<output>27_200</output>

<gadget id="calculator">27_200 + 1_250</gadget>
<output>28_450</output>

<result>28_450</result>