In a subtraction formula, the sum of the minuend, the subtrahend and the difference is 168, and the ratio of the subtrahend to the difference is 3:4. What is the subtrahend?
在一个减法算式中，被减数、减数、差三个数的和是168，减数与差的比是3：4，减数是多少．
<gadget id="calculator">168 / 2</gadget>
<output>84</output>

<gadget id="calculator">3 + 4</gadget>
<output>7</output>

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

<gadget id="calculator">84 * (3/7)</gadget>
<output>36</output>

<result>36</result>