A desk is 48 yuan, and a chair is 12 yuan cheaper than a desk. How much does it cost to buy such a set of desks?
一张课桌48元，一把椅子比一张课桌便宜12元．买这样的一套课桌需要多少元？
<gadget id="calculator">48 - 12</gadget>
<output>36</output>

<gadget id="calculator">36 + 48</gadget>
<output>84</output>

<result>84</result>