What is the quotient of the sum of 4 and 3.5 divided by their difference?
4与3.5的和除以它们的差，商是多少？
<gadget id="calculator">4 + 3.5</gadget>
<output>7.5</output>

<gadget id="calculator">4 - 3.5</gadget>
<output>0.5</output>

<gadget id="calculator">7.5 / 0.5</gadget>
<output>15</output>

<result>15</result>