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Leviafan [203]
3 years ago
12

The area of a circle varies directly with the square of its radius.if the area 4πcm² when the radius is 2cm, find the area when

the radius is 3cm
Mathematics
1 answer:
goldenfox [79]3 years ago
5 0

Answer:

A = 9π cm²

Step-by-step explanation:

Given that area (A) varies directly with r² then the equation relating them is

A = kr² ← k is the constant of variation

To find k use the condition A = 4π when r = 2 , then

4π = k × 2² = 4k ( divide both sides by 4 )

π = k

A = πr² ← equation

when r = 3 , then

A = π × 3² = 9π cm²

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Write the point-slope form of the equation of the line through the point (3,-5) with a slope of -4/3.
hodyreva [135]

Answer:

asda

Step-by-step explanation:

4 0
3 years ago
For 9x+25=88, Deens wrote the situation "I bought some shirts at the store for $9 each and received a $25 discount. My total bil
Sliva [168]
Total bill would be excluding the discount, so Deens has included the discount on the wrong side of the equation.

So: 9X = 88-25
9X=63
63/9=7
therefore Deens bought 7 shirts
7 0
3 years ago
The Ship It Anywhere Company bought a truck for $245,000. According to the company’s accounting department, the truck will depre
Svetradugi [14.3K]

Answer:

1. V(t) = -32500t + 245000

a. The slope of the function is m = -32500, and it means the change in the value of V(t) for each unitary change in the value of t.

b. The V-intercept is b = 245000, and it means the value of V(t) when t = 0, that is, the inicial value of V(t).

c. The formula is: V(t) = -32500t + 245000

2. t-intercept: t = 7.5385

The t-intercept means when the function V(t) will be zero, that is, the truck has no value anymore.

3. Graph in the image attached.

4. The domain is t = [0, 7.5385] and the range is V(t) = [245000, 0].

5. V(8) = -15000

It means the price the truck will have after 8 years. It does not make sense, because the truck can't have a negative price.

6. After 3.6 years.

7. Between 3.23 years and 5.63 years.

Step-by-step explanation:

1.

The inicial value is 245,000, and each year the value decreases 32,500, so we can write the equation:

V(t) = -32500t + 245000

a. The slope of the function is m = -32500, and it means the change in the value of V(t) for each unitary change in the value of t.

b. The V-intercept is b = 245000, and it means the value of V(t) when t = 0, that is, the inicial value of V(t).

c. The formula is: V(t) = -32500t + 245000

2.

To find the t-intercept we just need to use V(t) = 0 and then find the value of t:

0 = -32500t + 245000

32500t = 245000

t = 7.5385

The t-intercept means when the function V(t) will be zero, that is, the truck has no value anymore.

3.

The graph of the function is in the image attached.

4.

The domain is t = [0, 7.5385] and the range is V(t) = [245000, 0].

5.

V(8) = -32500*8 + 245000 = -15000

It means the price the truck will have after 8 years. It does not make sense, because the truck can't have a negative price.

6.

128000 = -32500t + 245000

32500t = 117000

t = 3.6

After 3.6 years.

7.

62000 = -32500t + 245000

32500t = 183000

t = 5.6308

140000 = -32500t + 245000

32500t = 105000

t = 3.2308

Between 3.23 years and 5.63 years.

5 0
3 years ago
Could you please help me thank you
stiks02 [169]

Answer:

2 (1/3) cups

Step-by-step explanation:

8 x 3(1/2) = 28 cups

28 / 12 = 2 (1/3) cups

3 0
3 years ago
( Math ) Please explain how you got this answer! Please use substitution method!
disa [49]

Answer:

y = 1

x = -2

Step-by-step explanation:

During the substitution method, you are substituting one function into another. Because both functions are set equal to "x", you can make the functions equal each other. This allows you to 'get rid' of the "x" variable and simplify to find the value of "y".

5A) x = -2y

5B) x = 2 - 4y

-2y = 2 - 4y                     <----- Set both equations equal

2y = 2                             <----- Add 4y to both sides

y = 1                                <----- Divide both sides by 2

Now that you know what "y" equals, you can plug that value into the "y" variable into one of the equations. This will allow you to then simplify and find the answer for "x".

x = -2y                             <----- Equation 5A

x = -2(1)                           <----- Plug 1 into "y"

x = -2                              <----- Multiply -2 and 1

5 0
2 years ago
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