What is the sum of 18 and 12 divided by their difference? What is the comprehensive formula.
18与12的和除以它们的差，结果是多少？列综合算式是多少．
<gadget id="calculator">18 + 12</gadget>
<output>30</output>

<gadget id="calculator">18 - 12</gadget>
<output>6</output>

<gadget id="calculator">30 / 6</gadget>
<output>5</output>

<result>5</result>