Question 388994
Let {{{j}}} = Jeff's age now
Let {{{s}}} = his Son's age now
{{{j + 9}}} = Jeff's age in 9 years
{{{s + 9}}} = Son's age in 9 years
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given:
(1) {{{j = 3s}}}
(2) {{{j + 9 = 2*(s + 9)}}}
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From (2):
{{{j + 9 = 2s + 18}}}
By substitution:
{{{3s + 9 = 2s + 18}}}
{{{s = 9}}}
and
{{{j = 3s}}}
{{{j = 27}}}
Jeff is 27 and his Son is 9
In 9 years, Jeff will be 36 and his Son will be 18