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2 years ago

Which is the simplified rational expression for r2-4r+5/r-4

Mathematics

1 answer:

Sliva [168]2 years ago

8 0

Step-by-step explanation:

$\frac{ {r}^{2} - 4r + 5}{r - 4} - \frac{ {r}^{2} + 2r - 8}{r - 4} \\ = \frac{ ({r}^{2} - 4r + 5) - ( {r}^{2} + 2r - 8) }{r + 4} \\ = \frac{ {r}^{2} - {r}^{2} - 4r - 2r + 5 - 8 }{r - 4} \\ = \frac{ - 6r - 3}{r - 4}$

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The two-way table shows the number of sport utility vehicles with certain features for sale at the car lot.

irinina [24]

A randomly selected car with no 4 wheel drive....so there are 40 cars with no 4 wheel drive

cars with 3rd row seats...that do not have 4 wheel drive...there are 12

so the probability is : 12/40 = 0.3 <==

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2 years ago

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The Hamden board of education wants to know how the community feels about building a new media center for the middle school. The

Aleks [24]

According to the statement above, The Hamden board of education called every tenth person on the registration list. So let's analyze each case:

The sample is not randomly chosen (FALSE)

Given that the statement doesn't tell us anything about the way they choose the sample, it is reasonable to conclude that this is a randomly chosen. They called every tenth person on the registration list until the number of people was 40.

The sample should be larger to give more reliable information (TRUE)

You did not have to use mathematics to determine that you would need more information to get a conclusion. You must increase the sample, that is, the sample must be larger to give a reliable information.

The sample size is too large to make inferences (False)

This is explained in the previous item. If the sample should be lager is because the size is not too large.

The sample size is too small to represent the population (TRUE

This is true because 40 voters represent barely 0.5% of the entire list. This list has 7300 voters, so getting the conclusion from this sample doesn't provide with a strong conclusion.

The sample size is too small and will show larger variation. (FALSE)

Although the sample size is too small, the sample size not necessarily will show variation. In fact, it is possible that it does not show any variation and most of the people feel well about building a new media center for the middle school but it doesn't mean that the whole community does.

The sample is invalid because it randomly chooses voters. (FALSE)

It is false because in probability studies the sample is chosen randomly, so you get conclusions about the whole population always taking samples that represent the population as a whole.

The sample size is too small and can lead to false inferences (TRUE)

You can get false conclusions given that the sample size is too small. It's important to note that the sample size supports the conclusion of the study, so the sample must increase to have a reliable study.

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2 years ago

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A cell tower is located 3 miles east and 4 miles north of the center of a small town. The cell tower has a coverage radius of 3

butalik [34]

Answer:

The answer is below

Step-by-step explanation:

A cell tower is located 3 miles east and 4 miles north of the center of a small town. The cell tower has a coverage radius of 3 miles.

a) Start by drawing a diagram of this situation. Your diagram might include a coordinate plane, the cell tower, and a circle representing the cell tower's coverage boundary.

a) A house is located 5 miles north of the center of the town and is to the east of the cell tower. If the house lies on the boundary of the cell tower's coverage, how far east of the center of the town is the house?

Answer:

Let the center of the town represent the origin (0,0). Also 1 unit = 1 mile. Since the cell tower is located 3 miles east and 4 miles north of the center of a small town, it is represented by A(3, 4)

The cell tower has a coverage of radius 3 miles. This can be represented by a circle with equation:

(x - a)² + (y - b)² = r². where (a,b) is the center of the circle and r is the radius. Hence:

(x - 3)² + (y - 4)² = 3²

(x - 3)² + (y - 4)² = 9

The diagram is drawn using geogebra.

b) The house is 5 miles north. It can be represented by y = 5 line.

To find the distance east of the house we have to substitute y = 5 and solve for x, hence:

(x - 3)² + (y - 4)² = 9

(x - 3)² + (5 - 4)² = 9

(x - 3)² + 1 = 9

(x - 3)² = 8

(x - 3) = √8

x - 3 = ±2.83

x = 3 ± 2.83

x = 5.83 or 1.83

Since it is to the east to the cell tower, hence x = 5.83.

Therefore the house is located 5.83 miles to the east of the cell tower

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2 years ago

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tia_tia [17]

The first answer is correct, if you go back by 5% each year you will see that.

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A parachute is descending at a rate of 28 feet per minute. Find the total change in the altitude of the parachute after 4 minute

BigorU [14]

Answer:

The total change in the altitude of the parachute after 4 minutes is 92 ft

Step-by-step explanation:

Here, we want to calculate the total change in the altitude of the parachute.

The rate of change per minute = 28 ft/m

Now in 4 minutes, the total altitude change will be;

28 ft/min * 4 min = 92 ft

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