Last year, a piece of agricultural and sideline products "Zhangsheng" was sold, among which "Duck Tongue" (duck tongue) sold for 105 yuan per kilogram, which was 39 yuan less than twice the original price. How much was the original price per kilogram? (solution by equation)
去年，农副产品"涨声"一片，其中"鸭扁你"(鸭舌)每千克卖到105元，比原价的2倍少39元，原价每千克多少元？(用方程解)
<gadget id="calculator">105 + 39</gadget>
<output>144</output>

<gadget id="calculator">144 / 2</gadget>
<output>72</output>

<result>72</result>