x*((3/4)+(5/6))=(2/3).
x*((3/4)+(5/6))=(2/3)．
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">5 / 6</gadget>
<output>5/6 = around 0.833333</output>

<gadget id="calculator">(3/4) + (5/6)</gadget>
<output>19/12 = around 1.583333</output>

<gadget id="calculator">(2/3) / (19/12)</gadget>
<output>8/19 = around 0.421053</output>

<result>8/19 = around 0.421053</result>