SOLUTION: joe can paint a room in 6 hours less than billy. if they can paint the room in 4 hours working together, how long would it take each to paint the room working alone? can you

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equation Customizable Word Problems -> SOLUTION: joe can paint a room in 6 hours less than billy. if they can paint the room in 4 hours working together, how long would it take each to paint the room working alone? can you      Log On


   

Question 126928:
joe can paint a room in 6 hours less than billy. if they can paint the room in 4 hours working together, how long would it take each to paint the room working alone?
can you please solve this using the quadratic equations?? thanks!!
Answer by checkley71(8403) About Me  (Show Source):
You can put this solution on YOUR website!
X(X-6)/[X+(X-6)]=4 NOW CROSS MULTIPLY
X(X-6)=4[X+(X-6)]
X^2-6X=4X+4X-24
X^2-6X-8X+24=0
X^2-14X+24=0
(X-2)(X-12)=0
X-12=0
X=12 HOURS FOR BILLY TO PAINT THE ROOM ALONE.
12-6=6 HOURS FOR JOE TO PAINT THE ROOM.
PROOF:
(12*6)/(12+6)=4
72/18=4
4=4