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:

The answer is
x=2t and t=x/2, but we have <span>y = 3t -1
so </span><span>y = 3(x/2) -1
so y = 3x/2 - 1</span>
54-15=39
if you want to check your answer you add 39+15=54
Answer:
x = 50
Step-by-step explanation:
101 + (x + 29) = 180
130 + x = 180
x = 180 - 130
x = 50