假设丢番图活了x年,
根据题意,得
(1/6+1/12+1/7)x+5+4=(1/2)x
解之得x=84,
丢番图开始当爸爸时的年龄(1/6+1/12+1/7)x+5=38
儿子死时的丢番图的年龄38+42=80
答案—解:(1)设丢番图活了x岁,那么
1/6x + 1/7x + 5 +1/2x + 11 = x
7/42x + 6/42x + 21/42 + 16 = x
x - 34/42x = 16
8/42x = 16
x = 84
(2) 84 X 1/2 = 42
(3) 84 X 1/7 = 12
答:丢番图结婚时是12岁,他儿子活了42岁,他活了84岁.
38,80
94