If a commodity is sold at 95% of the price, the profit is 84 yuan. If it is sold at 80% of the price, the loss is 36 yuan. What is the purchase price of the commodity?
某商品按定价的95%卖出可得利润84元，若按定价的80%出售，则亏损36元，则商品的购入价是多少元．
<gadget id="calculator">84 + 36</gadget>
<output>120</output>

<gadget id="calculator">95 / 100</gadget>
<output>19/20 = around 0.95</output>

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

<gadget id="calculator">(19/20) - (4/5)</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">120 / (3/20)</gadget>
<output>800</output>

<gadget id="calculator">800 * (19/20)</gadget>
<output>760</output>

<gadget id="calculator">760 - 84</gadget>
<output>676</output>

<result>676</result>