There is a trapezoid, if its upper base is increased by 2 meters and its lower base and height remain unchanged, its area will increase by 1.2 square meters; if its upper base, lower base and height are doubled, its area will be 9.6 square meters. What is the sum of the upper and lower bases of the trapezoid?
有一个梯形，如果它的上底增加2米，下底和高不变，它的面积就增加1.2平方米；如果上底、下底和高都扩大到原来的2倍，它的面积就是9.6平方米．原来梯形的上、下底之和是多少米．
<gadget id="calculator">2 * 2</gadget>
<output>4</output>

<gadget id="calculator">9.6 / 4</gadget>
<output>2.4</output>

<gadget id="calculator">2 / 1.2</gadget>
<output>1.666667</output>

<gadget id="calculator">2 / 2</gadget>
<output>1</output>

<gadget id="calculator">2.4 * 1.666667 * 1</gadget>
<output>4.000001</output>

<result>4.000001</result>