18 under and 4.25
1800 + 6
A = -2 if you do it all right
9514 1404 393
Answer:
C = 9x +2280
Step-by-step explanation:
The 2-point form of the equation for a line can be a place to start.
y = (y2 -y1)/(x2 -x1)(x -x1) +y1
C = (4800 -3000)/(280 -80)(x -80) +3000 . . . . . use given values
C = 1800/200(x -80) +3000 . . . . simplify some
C = 9x -720 +3000 . . . . eliminate parentheses
C = 9x +2280
speed with no wind = s
speed with wind = s + 5
speed against wind = s - 5
time = t
speed = distance/time
distance = speed * time
With wind, time = t, speed = s + 5, distance = 50
50 = (s + 5)t
Against wind, time = t, speed = s - 5, distance = 30
30 = (s - 5)t
t = 30/(s - 5)
50 = (s + 5) * 30/(s - 5)
50(s - 5) = (s + 5) * 30
50s - 250 = 30s + 150
20s = 400
s = 20
Answer: 20 mph