In △ABCD, P is a point in △ABD, and the area of △PBC is 5, and the area of △PAB is 2. What is the area of △PBD?
在▱ABCD中，P为△ABD内的一点，且△PBC面积为5，△PAB面积为2，△PBD的面积是多少？
<gadget id="calculator">5 - 2</gadget>
<output>3</output>

<result>3</result>