SOLUTION: I have a question over a worksheet I was given, my dad and I are stuck on how to set it up. It is over using the system of linear equations to find the present age.
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Question 175973: I have a question over a worksheet I was given, my dad and I are stuck on how to set it up. It is over using the system of linear equations to find the present age.
QUESTION: In 1987, Joy was 3 times as old as Ali. If Ali was born 8 years after Joy, what age will each be in 1999?
Please help. Thank You. Found 2 solutions by Alan3354, josmiceli:Answer by Alan3354(69443) (Show Source):
You can put this solution on YOUR website! In 1987, Joy was 3 times as old as Ali. If Ali was born 8 years after Joy, what age will each be in 1999?
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a = Ali's age in 1999
j = Joy's age in 1999
j = a + 8 (Joy was born 8 years after)
In 1987:
j-12 = 3*(a-12) (Joy was 3x Ali's age 12 years ago)
j-12 = 3a-36
Sub a+8 for j
(a+8) - 12 = 3a-36
a-4 = 3a-36
-2a = -32
a = 16 (in 1999)
j = 24 (in 1999)
You can put this solution on YOUR website! I'll reference their ages to 1999, and I'll say that at that year = Joy's age = Ali's age
Given:
In 1987, Joy's age was
In 1987, Ali's age was
(1)
The difference in their ages is 8 years and Ali is the younger, so
(2)
Substitute (2) in (1)
And, since
Joy is 24 and Ali is 16 in 1999
check:
(1)
(1)
OK
