This problem sounds odd because you normally would
think of being able to drive faster on freeways than
on side roads, but this problem has her driving
faster on the side roads.  Oh well, maybe it's
bumper-to-bumper on the freeway at rush hour. 

Make this chart.

                   Distance   Rate     Time
 On side roads      
 On freeway 

Let x = her rate on the freeway, so fill in x
for the rate on the freeway:

                   Distance   Rate     Time
 On side roads           
 On freeway                     x      

>>...60 miles using the side roads...<<

So fill in 60 for her distance using the side roads


                   Distance   Rate     Time
 On side roads        60       
 On freeway                     x      

>>...25 miles on the freeway...<<

So fill in 25 for her distance using the freeway


                   Distance   Rate     Time
 On side roads        60              
 On freeway           25        x     

>>...Ella's rate on the side roads is 7 mi/h faster than 
her rate on the freeway...<<

So add 7 to x, her rate on the freeway, to get x+7 and fill
that in for he rate on the side roads. 

                   Distance   Rate     Time
 On side roads        60       x+7       
 On freeway           25        x  

Next use Time = Distance/Rate to fill in both times:


                   Distance   Rate     Time
 On side roads        60       x+7    60/(x+7)
 On freeway           25        x      25/x

Now that the chart is filled in, we must make our equation.

>>...Ella can drive 60 miles using the side roads in the same
time that it takes to travel 25 miles on the freeway...<<

The key words are "same time".  When things are the same, they are
equal. So we set the two times equal.



All you have to do now is solve for x.

You get x = 5, so she traveled 5 mi/hr on the freeway. 

(Yes, it must be rush hour.  Why do they call it 
"rush hour" when nobody rushes at all?  :-)

Edwin