Question 978426
let f = father's present age
let s = son's
d = (f-s)
:
the sum total of the ages of father and son is 55 years.
f + s = 55
f = (55-s)
 if the father was to live till his sons age equal his present age, the total of their ages would be 93 years.
(f+d) + (s+d) = 93
f + s + 2d = 93
replace f with (55-s)
(55 - s) + s + 2d = 93
55 + 2d = 93
2d = 93 - 55
2d = 38
d = 38/2
d = 19 is the difference in their ages
:
Two equation we can use elimination
f + s = 55
f - s = 19
---------------adding eliminates s, find f
2f = 74
f = 74/2
f = 37 yrs is the father's age
37 - 19 = 18 yrs is the son's age