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3 years ago

Please help 4 questions for 10 points!!!

Mathematics

2 answers:

exis [7]3 years ago

8 0

Answer:

Step-by-step explanation:

1)4(20+3)

2)4(20+22)

3)6.40+6.5

4)12(2+7)

galben [10]3 years ago

8 0

I agree with the person above

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Half of the students in a freshman class are 14 years old. One-third are 15 and the rest are 13. Is the mean age greater than

Allisa [31]

the mean age is greater than the median age.

8 0

3 years ago

Fill in the missing number in this newspaper report:

natka813 [3]

Answer:

£125000

Step-by-step explanation:

Original cost of house = £100 000

Percent increase = 25%

Increase in price = 25% of 100,000

Increase in price = 0.25 * 100,000

Increase in price = 25000

New cost = original cost + Increment

New cost = 100,000 + 25,000

New cost = 125,000

Hence it now cost £125000

8 0

3 years ago

You purchase 5 pounds of apples and 2 pounds of oranges for $9.Your friend purchases 5 pounds of apples and 6 pounds of oranges

babymother [125]

Answer:

x = 1 and y = 2

Step-by-step explanation:

Let apples are represented by x

and let oranges are represented by y

You purchase 5 pounds of apples and 2 pounds of oranges for $9. This line in equation format can be written as:

5x + 2y = 9

Your friend purchases 5 pounds of apples and 6 pounds of oranges for $17.

This line in equation format can be written as:

5x + 6y = 17

Now we have two equations:

5x + 2y = 9 -> eq (i)

5x + 6y = 17 -> eq(ii)

We can solve these equations to find the value of x and y.

Subtracting eq(i) from eq(ii)

5x + 6y = 17

5x + 2y = 9

- - -

_________

0+4y= 8

=> 4y = 8

y= 8/4

y = 2

Now, putting value of y in eq (i)

5x + 2y = 9

5x +2(2) = 9

5x +4 = 9

5x = 9-4

5x = 5

x = 1

so, x = 1 and y = 2

8 0

3 years ago

Deviation is the difference between any value and the mean of the set.

faust18 [17]

The answer to this question is true. Based on my knowledge and research, the deviation is, in fact, the difference between any value and the mean of the entire set.

7 0

3 years ago

the volume v of a right circular cylinder of radius r and heigh h is V = pi r^2 h 1. how is dV/dt related to dr/dt if h is const

laiz [17]

In general, the volume

$V=\pi r^2h$

has total derivative

$\dfrac{\mathrm dV}{\mathrm dt}=\pi\left(2rh\dfrac{\mathrm dr}{\mathrm dt}+r^2\dfrac{\mathrm dh}{\mathrm dt}\right)$

If the cylinder's height is kept constant, then $\dfrac{\mathrm dh}{\mathrm dt}=0$ and we have

$\dfrac{\mathrm dV}{\mathrm dt}=2\pi rh\dfrac{\mathrm dt}{\mathrm dt}$

which is to say, $\dfrac{\mathrm dV}{\mathrm dt}$ and $\dfrac{\mathrm dr}{\mathrm dt}$ are directly proportional by a factor equivalent to the lateral surface area of the cylinder ( $2\pi r h$ ).

Meanwhile, if the cylinder's radius is kept fixed, then

$\dfrac{\mathrm dV}{\mathrm dt}=\pi r^2\dfrac{\mathrm dh}{\mathrm dt}$

since $\dfrac{\mathrm dr}{\mathrm dt}=0$ . In other words, $\dfrac{\mathrm dV}{\mathrm dt}$ and $\dfrac{\mathrm dh}{\mathrm dt}$ are directly proportional by a factor of the surface area of the cylinder's circular face ( $\pi r^2$ ).

Finally, the general case ( $r$ and $h$ not constant), you can see from the total derivative that $\dfrac{\mathrm dV}{\mathrm dt}$ is affected by both $\dfrac{\mathrm dh}{\mathrm dt}$ and $\dfrac{\mathrm dr}{\mathrm dt}$ in combination.

8 0

3 years ago