Question 118342
Let x = Dorthy's age 3 yrs ago
Let y = Dorileen's age 3 yrs ago
:
There present age will be: (x+3) and (y+3)
:
"The sum of the ages of Dorothy and Dorileen is 41."
(x+3) + (y+3) = 41
x + y + 6 = 41
x + y = 41 - 6
x + y = 35
x = (35 - y)
:
" In 5 years, Dorothy will be twice as old as Dorileen."
(That will be 8 yrs from 3 yrs ago)
x + 8 = 2(y + 8)
x + 8 = 2y + 16
x = 2y + 16 - 8
x = 2y + 8
:
"Find their ages 3 yrs ago"
Substitute (35-y) for x and find y
35 - y = 2y + 8
35 - 8 = 2y + y
3y = 27
y = 27/3
y = 9 yrs old is Dorileen's age 3 yrs ago
:
35 - 9 = 26 yrs is Dorthy's age 3 yrs ago
:
:
Check solution using the statement:
"The sum of the ages of Dorothy and Dorileen is 41."
(26+3) + (9+3) =
29 + 12 = 41
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