SOLUTION: John is three years older than Sue who is twice the age of David. write an expression for john's age in terms of D , David's age .

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Question 281583: John is three years older than Sue who is twice the age of David. write an expression for john's age in terms of D , David's age .
Found 2 solutions by Mathematicians, JBarnum:
Answer by Mathematicians(84) About Me  (Show Source):
You can put this solution on YOUR website!
First I will label my variables:
J = John
S = Sue
D = David
We know J = S + 3 from John is 3 years older than Sue
We know S = 2D from Sue is twice the age of David
Lastly, we know S = 2D, so why can't the S in J = S + 3 also be 2D
highlight+%28J+=+2D+%2B+3%29

Answer by JBarnum(2146) About Me  (Show Source):
You can put this solution on YOUR website!
J=john
S=sue
D=David
J=3%2BS
S=2D
substitue S for 2D
J=3%2B2D