Solve the equation: (1/3): x=(1/2): (3/7).
解方程：(1/3)：x=(1/2)：(3/7)．
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">3 / 7</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">(1/3) * (3/7)</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(1/7) / (1/2)</gadget>
<output>2/7 = around 0.285714</output>

<result>2/7 = around 0.285714</result>