Question 1174919
julia is 8 years older then dylan. 
j = d + 8
sofia is four years younger than dylan.
s = d - 4
 the sum of there ages is 55.
j + d + s = 55
 what is each persons age?
replace j with (d+8), replace s with (d-4)
(d+8) + d + (d-4) = 55
combine like terms
3d + 4 = 55
3d = 55 - 4
3d = 51
d = 51/3
d = 17 yrs is Dylan's age
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I'm sure you can find the other ages, ensure they all add up to 55