In a subtraction formula, the sum of the minuend, the subtrahend and the difference is 200, and the difference is 4 times the subtrahend. What is the difference?
在一个减法算式里，被减数、减数与差的和是200，差是减数的4倍，差是多少．
<gadget id="calculator">1 + 4 + 1 + 4</gadget>
<output>10</output>

<gadget id="calculator">200 / 10</gadget>
<output>20</output>

<gadget id="calculator">20 * 4</gadget>
<output>80</output>

<result>80</result>