The product of two factors is 84, one factor is doubled and the other factor is reduced by 4 times, what is the product
两个因数的积是84，一个因数扩大2倍，另一个因数缩小4倍，积是多少
<gadget id="calculator">4 / 2</gadget>
<output>2</output>

<gadget id="calculator">84 / 2</gadget>
<output>42</output>

<result>42</result>