Let's define variables:
s = original speed
s + 12 = faster speed
The time for the half of the route is:
60 / s
The time for the second half of the route is:
60 / (s + 12)
The equation for the time of the trip is:
60 / s + 60 / (s + 12) + 1/6 = 120 / s
Where,
1/6: held up for 10 minutes (in hours).
Rewriting the equation we have:
6s (60) + s (s + 12) = 60 * 6 (s + 12)
360s + s ^ 2 + 12s = 360s + 4320
s ^ 2 + 12s = 4320
s ^ 2 + 12s - 4320 = 0
We factor the equation:
(s + 72) (s-60) = 0
We take the positive root so that the problem makes physical sense.
s = 60 Km / h
Answer:
The original speed of the train before it was held up is:
s = 60 Km / h
Answer:
45
Step-by-step explanation:
Let the original number be xy where y is unit and x is tens hence original number is 10x+y When reversed, the new number is yz hence 10y+x
We know that the original number plus 9 is the reversed number hence
10x+y+9=10y+x
9y-9x=9 which when simplified we obtain that
y-x=1 equation 1
Originally, we are told that the sum of x and y is 9 hence
y+x=9 equation 2
Solving equation 1, it means y=x+1
Substituting the above into equation 2
x+1+x=9
2x=9-1
2x=8
x=8/2=4
Since y=x+1 then y=4+1=5
Therefore, the original number, xy is 45
Answer:
(-4, -1/2)
Step-by-step explanation:
Just by looking at the graph I can estimate that the midpoint of AB is (-4, -1/2) but we can also use midpoint formula to get a for sure answer.
Midpoint Formula: <em>((x1 + x2)/2, (y1 + y2)/2)</em>
x: (-5 + (-3))/2
-8 / 2
x = -4
y: (-4 + 3)/2
-1 / 2
y = -1/2
Answer:
4300
Step-by-step explanation:
i think this is what you want
