<PRE><B>Question 181753</B>
Your are traveling to a concert. To arrive on time you plan to travel at an
 average speed of 45 mph. For the first two hours of the trip you travel at
40 mph.
: 
Find the expression for the total time you traveled. 
:
Let t = time at 55 mph
Total time = t + 2
:
:
Then use the following verbal models to find how many hours you traveled at 55 mph to arrive on time
:
dist at 40 + dist at 55 = total dist
2(40) + 55t = total dist
;
ave speed *total time = total dist
45(t+2) = total dist
45t + 90 = total dist</PRE>