The sum of 2 times x and 3.6 is 8.4, find x.
x的2倍与3.6的和是8.4，求x．
<gadget id="calculator">8.4 - 3.6</gadget>
<output>4.8</output>

<gadget id="calculator">4.8 / 2</gadget>
<output>2.4</output>

<result>2.4</result>