Did you ever get the answer
The answer is 10.
4 a + 5 b when a = 4 and b = - 1.2
Answer:
40 mph
Step-by-step explanation:
We assume "outbound" refers to the trip <em>to the lake</em>. The ratio of speeds is inversely proportional to the ratio of times, so ...
outbound speed : inbound speed = 4 : 3
These differ by one ratio unit, so that one ratio unit corresponds to the speed difference of 10 mph. Then the 4 ratio units of outbound speed will correspond to ...
4×10 mph = 40 mph
Paul's average speed on the outbound trip was 40 mph.
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The distance to the lake was 120 mi.
