Question 770399
EDIT: Small change in first paragraph so explanation is more reliable.
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The question tells us that the distance to work is not known.  Let's call d this distance to work number.  We partial information about amount of time to reach work.


WHEN__________rate___________time hours_________distance
Monday________(__)___________35/60______________d
Tuesday_______(__)___________28/60______________d


We do not really know the traveling rates on those days either.  We only were given a difference in rate between the days, so we could use r, rate used on Monday.  Tuesday was used as 9 mph more than Monday:


WHEN__________rate___________time hours_________distance
Monday________(r)______________35/60______________d
Tuesday_______(r+9)___________28/60______________d


Next, we use the basic concept of rate, r*t=d, rate times time equals distance.  The distances of each day are equal.


Monday, {{{d=r*(35/60)}}}
Tuesday, {{{d=(r+9)*(28/60)}}}


{{{highlight(r(35/60)=(r+9)(28/60))}}}
Reaching this equation, whether the time hour fractions reduced or not, is MOST of the solution.  SOLVING for r is fairly straightforward algebra skills.  Use the value to find distance {{{d=r*(35/60)}}} or {{{d=r(7/12)}}}.