SOLUTION: A roofer and his assistant working together can finish a roofing job in 4 hours. The roofer working alone could finish the job in 6 hours less than the assistant working alone. How
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Question 351037: A roofer and his assistant working together can finish a roofing job in 4 hours. The roofer working alone could finish the job in 6 hours less than the assistant working alone. How long would it take the assistant working alone? Answer by edjones(8007) (Show Source):
You can put this solution on YOUR website! Let x=roofer's time and x+6 the assistants time to do the job.
In an hr roofer can do 1/x of the job and the asst. 1/(x+6) of the job.
1/x + 1/x+6 = 1/4
4(x+6)+4x=x(x+6) multiply each side by 4x(x+6)
4x+24+4x=x^2+6x
x^2-2x-24=0
(x-6)(x+4)=0
x=6 hrs
x+6=12 hrs the assistant working alone.
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Ed
