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3 years ago

Is y=-2/5x inverse or direct variation

Mathematics

1 answer:

liraira [26]3 years ago

3 0

Answer:

direct

Step-by-step explanation:

The standard form of an equation representing direct variation is

y = kx ← k is the constant of variation

The standard form of an equation representing inverse variation is

y = $\frac{k}{x}$ ← k is the constant of variation

y = - $\frac{2}{5}$ x ← represents direct variation with k = - $\frac{2}{5}$

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Sienna planned a rectangular pool, as shown in the scale drawing below.

svlad2 [7]

Answer:

The scale factor is

27.5 feet / 22 feet = 1.25.

Explanation:

Whenever you are calculating factors, you are comparing two measurements. In this problem we compared a longer length to a shorter length pool. The length was changed to (27.5 feet) and youre comparing to the length it was originally (22 feet).

Ok so you know the two measurements being compared, but how come it’s 27.5/22 and not 22/27.5? Because the value got bigger.

In this problem you had a pool with long side of 22 ft. But then you made it longer to 27.5 ft. So it scales up,

It went from 100% its length to 125% its length. So the length is 125% / 100% = 1.25 times longer than it used to be.

Here’s another example:

How do you calculate your grade percentage on a test? You take the amount of points you earned and divide by the total possible points. Your grade percentage is a comparison of your score (Compare value) compared to a perfect score (reference value) .

So lets say your test had 22 total points. You get all the answers correct so you get 22/22 points which is 22/22*100 = 100%. Let’s say you get an extra bonus question correct so you end up with even more points and you get 27.5 points out of 22. By getting the bonus points you scaled up your score! Now your score is 27.5/22 * 100 = 125%. So you went from 100% to a 125%. Or from a scale factor of 1 to 1.25.

Whenever the value is getting bigger than it was, you’re going to have a compared percentage over 100%. If the value gets smaller, then you would get a compared percentage less than 100%. Similarly a factor scale is going to be over 1 if the compared value is getting bigger, and less than 1 if it’s getting smaller.

So you don’t need to use percentages, factors are the same they just look a little different.

27.5/22 = 125% / 100% = 1.25

In summary just do this division:

(compare value)/(reference value). The result is how big the top value is compared to the bottom value.

5 0

3 years ago

Read 2 more answers

Pretty Pavers company is installing a driveway. Below is a diagram of the driveway they are

prohojiy [21]

Answer:

The most correct option is;

(B) 958.2 ft.²

Step-by-step explanation:

From the question, the dimension of each square = 3 ft.²

Therefore, the length of the sides of the square = √3 ft.

Based on the above dimensions, the dimension of the small semicircle is found by counting the number of square sides ti subtends as follows;

The dimension of the diameter of the small semicircle = 10·√3

Radius of the small semicircle = Diameter/2 = 10·√3/2 = 5·√3

Area of the small semicircle = (π·r²)/2 = (π×(5·√3)²)/2 = 117.81 ft.²

Similarly;

The dimension of the diameter of the large semicircle = 10·√3 + 2 × 6 × √3

∴ The dimension of the diameter of the large semicircle = 22·√3

Radius of the large semicircle = Diameter/2 = 22·√3/2 = 11·√3

Area of the large semicircle = (π·r²)/2 = (π×(11·√3)²)/2 = 570.2 ft.²

Area of rectangle = 11·√3 × 17·√3 = 561

Area, A of large semicircle cutting into the rectangle is found as follows;

$A_{(segment \, of \, semicircle)} = \frac{1}{4} \times (\theta - sin\theta) \times r^2$

Where:

$\theta = 2\times tan^{-1}( \frac{The \, number \, of \, vertical \, squrare \, sides \ cut \, by \ the \ large \, semicircle}{The \, number \, of \, horizontal \, squrare \, sides \ cut \, by \ the \ large \, semicircle} )$

$\therefore \theta = 2\times tan^{-1}( \frac{10\cdot \sqrt{3} }{5\cdot \sqrt{3}} ) = 2.214$

Hence;

$A_{(segment \, of \, semicircle)} = \frac{1}{4} \times (2.214 - sin2.214) \times (11\cdot\sqrt{3} )^2 = 128.3 \, ft^2$

Therefore; t

The area covered by the pavers = 561 - 128.3 + 570.2 - 117.81 = 885.19 ft²

Therefor, the most correct option is (B) 958.2 ft.².

4 0

3 years ago

g The bursar a conducts a test of hypothesis that the mean amount of student debt a WCU undergrad will leave college with is equ

aleksandrvk [35]

Answer: Type I error

Step-by-step explanation:

A type 1 error is also referred to as the false positive and it is when a true null hypothesis is incorrectly rejected by the researcher.

On the other hand, type II error which is also refered to as the false-negative is when a null hypothesis which is false is failed to be rejected by the researcher but rather accepted.

Based on the information given in the question, since the data leads to the rejection of the null hypothesis such was later found out to be true, then a type I error has occured.

4 0

3 years ago

Write an equation in point-slope form for the line that passes through each point.

frutty [35]

Answer:

You can't make a point=slope form equation.

Step-by-step explanation:

The vertical line would be parallel to y- axis, hence its equation would be x= c . The slope of the vertical line is undefined, therefore there is no point slope form as such.

4 0

3 years ago

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Find the sum of the measures of the interior angles in the figure shown.

ZanzabumX [31]

Step-by-step explanation:

A: 360/5=72

B:540/5=180

C:720/5=144

D:900/5=180

E:1260/5=252

8 0

4 years ago

Read 2 more answers