It is known that (6, 2)=8, (8, 3)=10, (11, 4)=14, ((5/6), (1/2))=(2/3); if ((1 /2), x)=(2/5), find x.
已知(6，2)=8，(8，3)=10，(11，4)=14，((5/6)，(1/2))=(2/3)；若((1/2)，x)=(2/5)，求x．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(1/2) * 2</gadget>
<output>1</output>

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

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">(3/5) / 2</gadget>
<output>3/10 = around 0.3</output>

<result>3/10 = around 0.3</result>