The cover of a magazine is a rectangle, the length is 30 cm, and the width is 6 cm less than the length. What is the area of the rectangle?
一本杂志的封面是长方形，长30厘米，宽比长少6厘米，这个长方形的面积是多少平方厘米？
<gadget id="calculator">30 - 6</gadget>
<output>24</output>

<gadget id="calculator">30 * 24</gadget>
<output>720</output>

<result>720</result>