3.5 times of a number is 17.1 less than its 7.3 times, what is this number?
一个数的3.5倍比它的7.3倍少17.1，这个数是多少？
<gadget id="calculator">7.3 - 3.5</gadget>
<output>3.8</output>

<gadget id="calculator">17.1 / 3.8</gadget>
<output>4.5</output>

<result>4.5</result>