SOLUTION: When my father was 32, I was 9. Now he is twice as old as I am. HOW OLD AM I? I've got the answer via guess and check but my teacher demands an equation. PLEASE HELP!

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Question 461830: When my father was 32, I was 9. Now he is twice as old as I am. HOW OLD AM I?
I've got the answer via guess and check but my teacher demands an equation. PLEASE HELP!
Answer by solver91311(24713) (Show Source):
You can put this solution on YOUR website!

This is one of those rare occasions when it is more convenient to choose a variable that represents a quantity other than the answer demanded by the question. While your first instinct might be to say, "Let represent your age now", it will be much more convenient to let represent the number of years since you were 9 years old.

If represents the number of years since you were 9, then your age today is and your father's age today is . And since the father is twice as old as the son today, we can write:

Solve for and then calculate

John

My calculator said it, I believe it, that settles it