If two cubes are put together to form a cuboid, the surface area is reduced by 18 square decimeters. What is the surface area of each cube?
把两个正方体拼成一个长方体，表面积减少了18平方分米，每个正方体的表面积是多少平方分米．
<gadget id="calculator">18 / 2</gadget>
<output>9</output>

<gadget id="calculator">9 * 6</gadget>
<output>54</output>

<result>54</result>