Solve the equation: ((2x-1.8)/5)=2.5.
解方程：((2x-1.8)/5)=2.5．
<gadget id="calculator">1.8 / 5</gadget>
<output>0.36</output>

<gadget id="calculator">0.36 + 2.5</gadget>
<output>2.86</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">2.86 / (2/5)</gadget>
<output>7.15</output>

<result>7.15</result>