In 2008, the age of the mother was 4 times the age of the older sister and the younger sister. In 2014, the age of the mother was twice the age of the older sister and the younger sister. When was the mother born?
2008年，妈妈的年龄是姐姐和妹妹年龄和的4倍，2014年妈妈的年龄是姐姐和妹妹年龄和的2倍，妈妈哪一年出生？
<gadget id="calculator">2 * 6</gadget>
<output>12</output>

<gadget id="calculator">12 - 6</gadget>
<output>6</output>

<gadget id="calculator">12 + 6</gadget>
<output>18</output>

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

<gadget id="calculator">18 / 2</gadget>
<output>9</output>

<gadget id="calculator">9 * 4</gadget>
<output>36</output>

<gadget id="calculator">2_008 - 36</gadget>
<output>1_972</output>

<result>1_972</result>