SOLUTION: A father has two sons whose age differ by 3 years. In 20 years time the sum of the son's ages will equal the father's age then. When the younger son was born, the father was nine t

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Question 930180: A father has two sons whose age differ by 3 years. In 20 years time the sum of the son's ages will equal the father's age then. When the younger son was born, the father was nine times as old as his elder son. Find the present ages of the father and his two sons.
Answer by TimothyLamb(4379) About Me  (Show Source):
You can put this solution on YOUR website!
x = father age
y = younger son age
z = older son age
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z - y = 3
y + 20 + z + 20 = x + 20
x - y = 9(z - y)
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put the system of linear equations into standard form
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-y + z = 3
x - y - z = 20
x + 8y - 9z = 0
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copy and paste the above standard form linear equations in to this solver:
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solution:
x = father age = 31
y = younger son age = 4
z = older son age = 7
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