Answer:
a
Step-by-step explanation:
Answer:
30 mph
Step-by-step explanation:
Let d = distance (in miles)
Let t = time (in hours)
Let v = average speed driving <u>to</u> the airport (in mph)
⇒ v + 15 = average speed driving <u>from</u> the airport (in mph)
Using: distance = speed x time

Create two equations for the journey to and from the airport, given that the distance one way is 18 miles:

We are told that the total driving time is 1 hour, so the sum of these expressions equals 1 hour:

Now all we have to do is solve the equation for v:







As v is positive, v = 30 only
So the average speed driving to the airport was 30 mph
(and the average speed driving from the airport was 45 mph)
Answer:
x = ±
- 2
Step-by-step explanation:
x² + 4x = 4
to complete the square
add ( half the coefficient of the x- term )² to both sides
x² + 2(2)x + 4 = 4 + 4
(x + 2)² = 8 ( take square root of both sides )
x + 2 = ±
( subtract 2 from both sides )
x = ±
- 2
X is 10 take that’s known 80 degrees and the fact that it is a right angle means the whole this is 90 degrees so therefore x is 10 90=80+_