Answer: 
Step-by-step explanation:
Given: A tourist first walked 17km with a speed of v km/h.
Since 
therefore, 
Let 
be the time he walked with speed v.
then 
Also he hiked 12 km uphill with the speed that was 2 km/hour less than his original speed.
Let 
be the time he hiked 12 km,
Then 
The total time for the whole trip is given by:-
Substitute the values of and in the equation, we get
You have to multiply 7 3/4 to 9.
First, turn 7 3/4 to an improper fraction which is 31/4.
Next, you multiply 31/4 to 9/1(same thing as 9) across from each other.
Then, you get the answer 279/4(31 x 9 = 279 ;4 x 1 = 4; 279/4).
Last divide 279 to 4 and get 67.75( .75 = 3/4 ; 69 3/4).
