If the width of a rectangle is increased by 4 cm, it becomes a square, and the area increases by 48 cm2. Find the area of the original rectangle.
一个长方形的宽增加4厘米，就成了一个正方形，这样面积就增加了48平方厘米，求原来长方形的面积．
<gadget id="calculator">48 / 4</gadget>
<output>12</output>

<gadget id="calculator">12 - 4</gadget>
<output>8</output>

<gadget id="calculator">12 * 8</gadget>
<output>96</output>

<result>96</result>