Question 1149621
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Let x be the Joseph's age.

Then the father's age is 7x years.



One age ago 


    7x-1 = 9*(x-1)


Simplify and solve


    7x - 1 = 9x - 9

    9 - 1 = 9x - 7x

    8 = 2x.

    x = 8/2 = 4.


<U>ANSWER</U>.  4 years and 28 years.
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