SOLUTION: Trying to solve this with my children... Problem: Mr. Black is three times as old as his son Jerry. Nine years ago he was nine times as old as Jerry. Solution suppose to be

Algebra ->  Human-and-algebraic-language -> SOLUTION: Trying to solve this with my children... Problem: Mr. Black is three times as old as his son Jerry. Nine years ago he was nine times as old as Jerry. Solution suppose to be       Log On


   



Question 589540: Trying to solve this with my children...
Problem:
Mr. Black is three times as old as his son Jerry. Nine years ago he was nine times as old as Jerry.
Solution suppose to be (according to the teacher manual):
3x-9=9(x-9)
I cannot figure out why...
Please help

Answer by stanbon(75887) About Me  (Show Source):