After the death of the ancient Greek mathematician Diophantus, an interesting sentence was engraved on his tombstone. The general idea is: "In Diophantus's life, childhood accounted for (1/6), adolescents accounted for (1/12), and after another life (1/7) did not get married, 5 years later had a child, and the child died earlier than him 4 Years, half of his father's lifespan." Please calculate the age of Diophantus' death according to the meaning of the inscription.
古希腊数学家丢番图去世后，他的墓碑上刻着一段有趣的话．大意是："丢番图的一生，幼年占(1/6)，青少年占(1/12)，又过了一生的(1/7)才结婚，5年之后生子，子比他早去世4年，寿命是他父亲的一半．"请你根据碑文的意思算出丢番图过世的年龄．
<gadget id="calculator">5 + 4</gadget>
<output>9</output>

<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">1 / 12</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">1 / 7</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 - (1/6) - (1/12) - (1/7) - (1/2)</gadget>
<output>3/28 = around 0.107143</output>

<gadget id="calculator">9 / (3/28)</gadget>
<output>84</output>

<result>84</result>