0.6*(3.8-x)=1.5.
0.6*(3.8-x)=1.5．
<gadget id="calculator">0.6 * 3.8</gadget>
<output>2.28</output>

<gadget id="calculator">2.28 - 1.5</gadget>
<output>0.78</output>

<gadget id="calculator">0.78 / 0.6</gadget>
<output>1.3</output>

<result>1.3</result>