169 if you take 13 times 3 you get 39. And 10 times 13 is 130. Add those together and you gat 169
Average speed for the entire trip, both ways, is
(Total distance) divided by (total time) .
We don't know the distance from his house to the gift store,
and we don't know how long it took him to get back.
We'll need to calculate these.
-- On the trip TO the store, it took him 50 minutes, at 6 mph.
-- 50 minutes is 5/6 of an hour.
-- Traveling at 6 mph for 5/6 of an hour, he covered 5 miles.
-- The gift store is 5 miles from his house.
-- The total trip both ways was 10 miles.
-- On the way BACK home from the store, he moved at 12 mph.
-- Going 5 miles at 12 mph, it takes (5/12 hour) = 25 minutes.
Now we have everything we need.
Distance:
Going: 5 miles
Returning: 5 miles
Total 10 miles
Time:
Going: 50 minutes
Returning: 25 minutes
Total: 75 minutes = 1.25 hours
Average speed for the whole trip =
(total distance) / (total time)
= (10 miles) / (1.25 hours)
= (10 / 1.25) miles/hours
= 8 miles per hour
Differentiating both sides of

with respect to
yields

At the point (3, 4) (so
and
), the tangent line has slope

Then the tangent line to (3, 4) has equation

Answer:
ebhats
Step-by-step explanation: