A subtraction formula, the sum of the minuend, the subtrahend and the difference is 528, and the subtrahend is twice the difference, what is the subtrahend.
一道减法算式，被减数、减数、差的和是528，又知减数是差的2倍，减数是多少．
<gadget id="calculator">1 + 2 + 1 + 2</gadget>
<output>6</output>

<gadget id="calculator">528 / 6</gadget>
<output>88</output>

<gadget id="calculator">88 * 2</gadget>
<output>176</output>

<result>176</result>