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
Sales tax is a percentage of the sale price of an item that is then added on to the total price of the item.
Example:
let's say you are buying an item priced at $10.00 and the sales tax rate is 6%. Sales tax rates can vary from state to state and even within counties or cities.
Answer: 85 baseball cards
Explanation: If Doug has 5 baseball cards for every four football cards, that means he has 125%, or 1.25x as many baseball cards as basketball cards at any given moment. If he has 68, we can multiply 68 by 1.25 and get 85 baseball cards
Answer:
2π or 0π are the only points that satisfy the expression, but since the restriction is 0 <= x < 2π
the answer would be 0π
