The sum of 4 times a number and 5.5 times it is 1.9, what is this number?
一个数的4倍与它的5.5倍的和是1.9，这个数是多少？
<gadget id="calculator">4 + 5.5</gadget>
<output>9.5</output>

<gadget id="calculator">1.9 / 9.5</gadget>
<output>0.2</output>

<result>0.2</result>