Answer:
50 km/hr
Step-by-step explanation:
OK, this is how I solved this problem.
Let r = original rate of speed
t = time after the stop to finish the trip
Time for trip without stopping is 225/r
(1) 1.5 + .5 + t = 225/r This is a time equation
(2) 1.5r + t(r + 10) = 225 This is a distance equation
(1) 2 + t = 225/r (2) 1.5r + tr + 10t = 225
2r + tr = 225
tr = 225 - 2r 1.5r + 225 - 2r + 10(225/r - 2) = 225
t = 225/r - 2
-.5r + 225 + 2250/r - 20 = 225
-5r + 2250 + 22500/r - 200 = 2250
-5r^2 + 2250r + 22500 - 200r = 2250r
5r^2 + 200r - 22500 = 0
5(r^ + 40r - 4500) = 0
5(r - 50)(r + 90) = 0
r = 50 or r = -90
The rate cannot be negative, so the original speed 50 km/hr
This not an easy problem and I hope you were able to follow my work
Answer:
4(aaa - 44) = 64
Step-by-step explanation:
I think this is right.
Answer:
B. Pyramid
Step-by-step explanation:
To minimize the cost, we take the straight distance from the refinery to the other side of the river as 2 km. Also, the 7 km will be the distance that has to be traveled by the pipeline in land. The total cost, C, is therefore,
total cost = (2 km)($800,000/km) + (7 km)($400,000 /km)
total cost = $4,400,000
Thus, the total cost of the pipeline is approximately $4,400,000.00.
Answer:
Presumably you're solving for x here? Without further information we'll assume that.
With that in mind, x is approximately equal to 0.86 and -0.46
Step-by-step explanation:
Let's start by putting it in the usual ax² + bx + c format.
let's solve it. First we'll multiply both sides by five, making the first term a perfect square:
Now we'll add 11 to both sides:
Which makes the left side a perfect square:
And now we can solve for x:
Note that there's no apparent way of drawing the ± symbol when editing equations, so take that + sign as actually being ±.
That gives us two answers:
