If the side length of a square increases by 3 cm, the area increases by 45 cm2. What is the area of the original square?
一个正方形的边长增加3厘米，面积就增加45平方厘米，原来正方形的面积是多少．
<gadget id="calculator">3 * 3</gadget>
<output>9</output>

<gadget id="calculator">45 - 9</gadget>
<output>36</output>

<gadget id="calculator">3 + 3</gadget>
<output>6</output>

<gadget id="calculator">36 / 6</gadget>
<output>6</output>

<gadget id="calculator">6 * 6</gadget>
<output>36</output>

<result>36</result>