In 1996, the father's age was 4 times the age of the older sister and the younger sister. In 2004, the father's age was twice the age of the older sister and the younger sister. When was the father born?
1996年爸爸的年龄是姐姐和妹妹年龄和的4倍，2004年爸爸的年龄是姐姐和妹妹年龄和的2倍，爸爸是多少年出生的．
<gadget id="calculator">2 * 8</gadget>
<output>16</output>

<gadget id="calculator">16 - 8</gadget>
<output>8</output>

<gadget id="calculator">16 + 8</gadget>
<output>24</output>

<gadget id="calculator">4 - 2</gadget>
<output>2</output>

<gadget id="calculator">24 / 2</gadget>
<output>12</output>

<gadget id="calculator">12 * 4</gadget>
<output>48</output>

<gadget id="calculator">1_996 - 48</gadget>
<output>1_948</output>

<result>1_948</result>