rectangular field, no matter if the length is increased by 4m or the width is increased by 3m, the area will increase by 240m**2. What is the area of this field in m**2.
一块长方形的田，无论长增加4m，或是宽增加3m，面积都比原来增加240米**2．这块田的面积是多少m**2．
<gadget id="calculator">240 / 3</gadget>
<output>80</output>

<gadget id="calculator">240 / 4</gadget>
<output>60</output>

<gadget id="calculator">80 * 60</gadget>
<output>4_800</output>

<result>4_800</result>