SOLUTION: Genelle and Eljen can paint a room together in 4 hours. Working alone, Genelle can paint the room in two hours less than Eljen can. Find how long it takes Eljen to paint the room a

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: Genelle and Eljen can paint a room together in 4 hours. Working alone, Genelle can paint the room in two hours less than Eljen can. Find how long it takes Eljen to paint the room a      Log On


   

Question 241499: Genelle and Eljen can paint a room together in 4 hours. Working alone, Genelle can paint the room in two hours less than Eljen can. Find how long it takes Eljen to paint the room alone.
Answer by checkley77(12844) About Me  (Show Source):
You can put this solution on YOUR website!
g=e-2
g*e/(g+e)=4
(e-2)e/(e-2+e)=4
e^2-2e/(2e-2)=4 cross multiply.
e^2-2e=4(2e-2)
e^2-2e=8e-8
e^2-2e-8e+8=0
e^2-10e+8=0
e+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
e=(10+-sqrt[-10^2-4*1*8])/2*1
e=(10+-sqt100-32)/2
e=(10+-sqrt68)/2
e=(10+-8.246/2
e=(10+8.246)/2
e=18.246/2
e=9.123 ans.
g=9.123-2=7.123 ans.
Proof:
9.123*7.123/(9.123+7.123)=4
64.983/16.246=4
4~4