Given a trapezoidal flower bed, its area is 1.05 square meters. Its bottom is 1.8 meters, its height is 0.7 meters, how many meters is its top bottom? (solution by equation)
已知一个梯形花坛，它的面积是1.05平方米．它的下底是1.8米，高是0.7米，上底是多少米？(用方程解)
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1.8 * (1/2)</gadget>
<output>0.9</output>

<gadget id="calculator">0.7 * (1/2)</gadget>
<output>0.35</output>

<gadget id="calculator">0.9 + 0.35</gadget>
<output>1.25</output>

<gadget id="calculator">1.05 / 1.25</gadget>
<output>0.84</output>

<result>0.84</result>