There is a racecourse, the width is 150 meters, and the length is 20 meters less than twice the width. What is the area of the racetrack?
有一个跑马场，宽150米，长比宽的2倍少20米．这个跑马场的面积有多少？
<gadget id="calculator">150 * 2</gadget>
<output>300</output>

<gadget id="calculator">300 - 20</gadget>
<output>280</output>

<gadget id="calculator">280 * 150</gadget>
<output>42_000</output>

<result>42_000</result>