It is known that the area of a trapezoid is 24dm**2. His lower bottom is 8dm, his height is 4dm, how many decimeters is his upper bottom? (column equation solution)
已知一个梯形的面积是24dm**2．他的下底是8dm，高是4dm，上底是多少分米？(列方程解答)
<gadget id="calculator">4 / 2</gadget>
<output>2</output>

<gadget id="calculator">8 * 2</gadget>
<output>16</output>

<gadget id="calculator">24 - 16</gadget>
<output>8</output>

<gadget id="calculator">8 / 2</gadget>
<output>4</output>

<result>4</result>