Solve the equation: 2: (1+x)=(4/5).
解方程：2：(1+x)=(4/5)．
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">2 - (4/5)</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">(6/5) / (4/5)</gadget>
<output>3/2 = around 1.5</output>

<result>3/2 = around 1.5</result>