In a subtraction formula, if the sum of the minuend, the subtrahend and the difference is 80, what is the minuend?
在一道减法算式里，被减数、减数与差相加的和是80，则被减数是多少．
<gadget id="calculator">80 / 2</gadget>
<output>40</output>

<result>40</result>