Three tractors, A, B, and C, jointly plow a piece of land. A plows 40% of the land. The ratio of the arable land between B and C is 5:4. B plows 100 hectares less than A. How many hectares did tractor B plow?
甲、乙、丙三台拖拉机合耕一块地，甲耕了这块地的40%，乙与丙耕地面积比是5：4，乙比甲少耕100公顷．乙拖拉机耕了多少公顷？
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">5 + 4</gadget>
<output>9</output>

<gadget id="calculator">5 / 9</gadget>
<output>5/9 = around 0.555556</output>

<gadget id="calculator">(3/5) * (5/9)</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(2/5) - (1/3)</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">100 / (1/15)</gadget>
<output>1_500</output>

<gadget id="calculator">1_500 * (3/5) * (5/9)</gadget>
<output>500</output>

<result>500</result>