2.5(x-1.6)=41*0.5.
2.5(x-1.6)=41*0.5．
<gadget id="calculator">2.5 * 1.6</gadget>
<output>4</output>

<gadget id="calculator">41 * 0.5</gadget>
<output>20.5</output>

<gadget id="calculator">4 + 20.5</gadget>
<output>24.5</output>

<gadget id="calculator">24.5 / 2.5</gadget>
<output>9.8</output>

<result>9.8</result>