This year is 2012 AD, the sum of the ages of the parents is 78 years old, and the sum of the ages of the brothers is 17 years old. Four years later, the age of the father is four times that of the brother, and the age of the mother is three times that of the brother. Then, when the father's age is twice the elder brother's age, how many years in AD.
今年是公元2012年，父母的年龄和是78岁，兄弟的年龄和是17岁．四年后，父亲的年龄是弟弟的4倍，母亲的年龄是哥哥的3倍．那么，当父亲年龄是哥哥年龄的2倍时是公元多少年．
<gadget id="calculator">17 + 8</gadget>
<output>25</output>

<gadget id="calculator">25 * 4</gadget>
<output>100</output>

<gadget id="calculator">78 + 8</gadget>
<output>86</output>

<gadget id="calculator">100 - 86</gadget>
<output>14</output>

<gadget id="calculator">4 - 3</gadget>
<output>1</output>

<gadget id="calculator">14 / 1</gadget>
<output>14</output>

<gadget id="calculator">25 - 14</gadget>
<output>11</output>

<gadget id="calculator">11 * 4</gadget>
<output>44</output>

<gadget id="calculator">44 - 4</gadget>
<output>40</output>

<gadget id="calculator">14 - 4</gadget>
<output>10</output>

<gadget id="calculator">40 - 10</gadget>
<output>30</output>

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

<gadget id="calculator">30 / 1</gadget>
<output>30</output>

<gadget id="calculator">2_012 + 30</gadget>
<output>2_042</output>

<result>2_042</result>