College Algebra
posted by Laowe on .
It takes Todd 3 hours longer than Tom to paint a 4x5 feet bedroom. Working together, both can complete the job in two hours.How long does it take each one to complete the painting job working alone?

Let it takes Todd X hours; Tom Y hours.
X=Y+3
For one hour, Todd paints 1/X part of the bedroom, Tom  1/Y; together  1/X+1/Y
1/(1/X+1/Y)=2
2(X+Y)=XY
2(2Y+3)=(Y+3)Y
4Y+6=Y^2+3Y
Y^2Y6=0 => Y=3, X=6