What is the quotient of the difference of 7.5 minus 1.5 divided by the sum of 8.1 plus 4.5?
7.5减去1.5的差去除8.1加上4.5的和，商是多少？
<gadget id="calculator">8.1 + 4.5</gadget>
<output>12.6</output>

<gadget id="calculator">7.5 - 1.5</gadget>
<output>6</output>

<gadget id="calculator">12.6 / 6</gadget>
<output>2.1</output>

<result>2.1</result>