Answer:
1.) 2x-y=-7 --> y=2x + 7
2.) 5x+3y=12 --> y= -5/3x + 4
3.) x-y=1 --> y= x- 1
4.) x-3y=-15 --> y=1/3x + 5
5.) 8x-10y=20 --> y=4/5x - 2
6.) 14x+6y=36 --> y=-7/3x+6
Step-by-step explanation:
Hope this helped.
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)