Answer:
5/8
Step-by-step explanation:
a) 
The average speed is equal to the ratio between the total distance (
and the total time taken (
):

the distance travelled by the trucker in the first 3 hour can be written as the time multiplied by the velocity:

So the total distance is

The total time is equal to the first 3 hours + the time taken to cover the following 20 miles in the city:

So, the equation can be rewritten as:

b) 0.50 h (half a hour)
Since we know the value of the average speed,
, we can substitute it into the previous equation to find the value of
, the time the trucker drove in the city:

As an equation, we have:
69+42=5+(146-x)
You just have to simplify:
111=5+(146-x)
106=146-x
-40=-x
40=x
Your unknown number is 40
Answer:x=100
Step-by-step explanation:
Since you know that g(x)=3x-11 all you have to do is substitute that into g(x)=289. So you get 3x-11=289. To get x you have to add 11 on both sides.
3x-11=289
+11 +11
----------------
3x = 300
Divide 3 on both sides to get x by itself
3x =300
---- -------
3 3
x=100