SOLUTION: 1) Working alone, Coleen can paint a house in 2hr less than James. Working together, they can paint the house in 10hr. How long would it take James to paint the house?

Question 127987: 1) Working alone, Coleen can paint a house in 2hr less than James. Working together, they can paint the house in 10hr. How long would it take James to paint the house?
Answer by checkley71(8403) (Show Source): You can put this solution on YOUR website!
J(J-2)/[J+(J-2)]=10
(J^2-2J)/(2J-2)=10 NOW CROSS MULTIPLY
J^2-2J=10(2J-2)
J^2-2J=20J-20
J^2-2J-20J+20=0
J^2-22J+20
USING THE QUADRATIC EQUATION: WE GET:
J=(22+-SQRT[-22^2-4*1*20])/2*1
J=(22+-SQRT[484-80])/2
J=(22+-SQRT404)/2
J=(22+-20.1)/2
J=(22+20.1)/2
J=42.01/2
J=21.05 HOURS - TIME FOR JAMES TO PAINT THE HOUSE ALONE.
PROOF:
21.05*19.05/(21.05+19.05)=10
401/40.1=10
10=10

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