The sum of the minuend, the subtrahend and the difference is 52, the ratio of the subtrahend and the difference is 6:7, find the subtrahend.
被减数、减数和差的和是52，减数和差的比是6：7，求减数．
<gadget id="calculator">2 * 6</gadget>
<output>12</output>

<result>12</result>