Answer:the plane in still air is 904 km/h
the rate of the wind is 104 km/h
Step-by-step explanation:
Let x represent the rate or speed of the plane in still air.
Let y represent the rate or speed of the wind.
Flying against the wind, an airplane travels 4000 kilometers in 5 hours. This means that the total speed of the airplane would be (x - y) km/h
Distance = speed × time
Therefore
4000 = 5(x - y)
4000 = 5x - 5y - - - - - - - - -1
Flying with the wind, the same plane travels 5040 kilometers in 4 hours. This means that the total speed of the airplane would be (x + y) km/h. Therefore,
5040 = 4(x + y)
5040 = 4x + 4y - - - - - - - - - 2
Multiplying equation 1 by 4 and equation 2 by 5, it becomes
16000 = 20x - 20y
20160 = 20x + 20y
Subtracting, it becomes
- 4160 = - 40y
y = - 4160/-40
y = 104
Substituting y = 104 into equation 1, it becomes
4000 = 5x - 5 × 104
4000 = 5x - 520
5x = 4000 + 520
5x = 4520
x = 4520/5 = 904
Answer:
B. y = 2x - 9
Step-by-step explanation:
All of the answer choices has a slope of 2, but B is the only answer choice that has (4,-1) on its line.
You can tell by plugging the point into the equation and seeing if the result is true.
y = 2x - 9
-1 = 2(4) - 9
-1 = 8 - 9
-1 = -1
Hello,
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Answer B
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2x²+28x-5=2(x²+2*7x+49)-5-2*49=2(x+7)²-103
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Answer:
Required Probability = 0.97062
Step-by-step explanation:
We are given that the weights of newborn baby boys born at a local hospital are believed to have a normal distribution with a mean weight of 4016 grams and a standard deviation of 532 grams.
Let X = weight of the newborn baby, so X ~ N(
)
The standard normal z distribution is given by;
Z = 
~ N(0,1)
Now, probability that the weight will be less than 5026 grams = P(X < 5026)
P(X < 5026) = P( < 
) = P(Z < 1.89) = 0.97062
Therefore, the probability that the weight will be less than 5026 grams is 0.97062 .
It seems most likely that ...
... Samantha will save $37.50 because she must first find the 25% sale price before taking the extra 50% reduction
_____
In the real world, it seems probable that Samantha will be offered the choice of using the coupon <em>or</em> the sale discount. If she chooses tht 50% coupon, her savings will be $30. If she chooses the marked sale discount, her savings will be $15.
The scenario above assumes she gets 50% off the sale price of $45, so saves $15+22.50 = $37.50 off the original price.
