# SOLUTION: Alex and Boy working together can complete a job in 7 1\2 hours. Working alone, Alex takes 8 hours longer than Boy to do the job. How long would it take each working alone?helllpp

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 Question 130522: Alex and Boy working together can complete a job in 7 1\2 hours. Working alone, Alex takes 8 hours longer than Boy to do the job. How long would it take each working alone?helllpp me...Answer by edjones(7569)   (Show Source): You can put this solution on YOUR website!b=hours it takes boy to do the job. b+8=hours it takes Alex to do the job. 1/b=part of the job Boy can do in 1 hr. 1/(b+8)=part of the job Alex can do in 1 hr. Together they can complete a job in 15/2 hours so they can do 2/15 of the job in one hour. 1/b + 1/(b+8) = 2/15 15(b+8)+15b=2b(b+8) multiply each side by 15b(b+8) to eliminate fractions. 15b+120+15b=2b^2+16b 2b^2+16b-15b-15b-120=0 2b^2-14b-120=0 2(b^2-7b-60)=0 (b-12)(b+5)=0 b=12 hrs it takes Boy working alone. b+8=20 hrs it takes Alex working alone. . Ed