SOLUTION: Suzy and Charolette are involved in a service project helping ederly neighbors fix up their yards for summer. If it takes Suzy 9 hours to do the job on her own, and it takes them 4

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equation Customizable Word Problems -> SOLUTION: Suzy and Charolette are involved in a service project helping ederly neighbors fix up their yards for summer. If it takes Suzy 9 hours to do the job on her own, and it takes them 4      Log On


   

Question 89237: Suzy and Charolette are involved in a service project helping ederly neighbors fix up their yards for summer. If it takes Suzy 9 hours to do the job on her own, and it takes them 4 hours working together, how long will it take Charolette to fix up the yard by herself?
Answer by checkley75(3666) About Me  (Show Source):
You can put this solution on YOUR website!
9Y/(9+Y)=4 NOW CROSS MULTIPLY.
9Y=4(9+Y)
9Y=36+4Y
9Y-4Y=36
5Y=36
Y=36/5
Y=7.2 HOURS FOR CHARLOTTE TO DO THE JOB ALONE.
PROOF
9*7.2/(9+7.2)=4
64.8/16.2=4
4=4