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3 years ago

Write an equation rectangular room 3 meters longer than it is wide and its perimeter is 18 meters

Mathematics

1 answer:

Anon25 [30]3 years ago

3 0

width = x

length = 3 + x

perimeter = x + x + ( 3 + x ) + (3+x)

18 = x + x + ( 3 + x ) + (3+x)

x + x + ( 3 + x ) + (3+x) = 18

6 + 4x = 18

4x = 12

x = 3

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A standard bowling ball cannot be more than 27 inches in circumference. What is the maximum volume of such a ball (to the neares

ddd [48]

Answer:

333 in^3

Step-by-step explanation:

Circumference = pi *d

27 = pi*d

Replacing d with 2*r ( 2 times the radius)

27 = pi * 2 * r

Divide each side by 2

27/2 = pi *r

13.5 = pi *r

Divide by pi

13.5/ pi = r

We want to find the volume of a sphere

V = 4/3 pi * r^3

V = 4/3 pi (13.5/pi)^3

= 4/3 pi * (13.5)^3 / (pi^3)

4/3 pi/pi^3 * (13.5)^3

4/3 * 1/ pi^2 *2460.375

3280.5 / pi^2

Let pi be approximated by 3.14

380.5/(3.14)^2

332.7214086 in^3

To the nearest in^3

333 in^3

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3 years ago

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-1/8 x 5 x 2/3 equals what

ki77a [65]

-0.416 (6 repeatees forever) in decimal form

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3 years ago

A common assumption in modeling drug assimilation is that the blood volume in a person is a single compartment that behaves like

mixas84 [53]

Answer:

a) $\mathbf{\dfrac{dx}{dt} = 30 - 0.015 x}$

b) $\mathbf{x = 2000 - 2000e^{-0.015t}}$

c) the steady state mass of the drug is 2000 mg

d) t ≅ 153.51 minutes

Step-by-step explanation:

From the given information;

At time t= 0

an intravenous line is inserted into a vein (into the tank) that carries a drug solution with a concentration of 500

The inflow rate is 0.06 L/min.

Assume the drug is quickly mixed thoroughly in the blood and that the volume of blood remains constant.

The objective of the question is to calculate the following :

a) Write an initial value problem that models the mass of the drug in the blood for t ≥ 0.

From above information given :

$Rate _{(in)}= 500 \ mg/L \times 0.06 \ L/min = 30 mg/min$

$Rate _{(out)}=\dfrac{x}{4} \ mg/L \times 0.06 \ L/min = 0.015x \ mg/min$

Therefore;

$\dfrac{dx}{dt} = Rate_{(in)} - Rate_{(out)}$

with respect to x(0) = 0

$\mathbf{\dfrac{dx}{dt} = 30 - 0.015 x}$

b) Solve the initial value problem and graph both the mass of the drug and the concentration of the drug.

$\dfrac{dx}{dt} = -0.015(x - 2000)$

$\dfrac{dx}{(x - 2000)} = -0.015 \times dt$

By Using Integration Method:

$ln(x - 2000) = -0.015t + C$

$x -2000 = Ce^{(-0.015t)$

$x = 2000 + Ce^{(-0.015t)}$

However; if x(0) = 0 ;

Then

C = -2000

Therefore

$\mathbf{x = 2000 - 2000e^{-0.015t}}$

c) What is the steady-state mass of the drug in the blood?

the steady-state mass of the drug in the blood when t = infinity

$\mathbf{x = 2000 - 2000e^{-0.015 \times \infty }}$

x = 2000 - 0

x = 2000

Thus; the steady state mass of the drug is 2000 mg

d) After how many minutes does the drug mass reach 90% of its stead-state level?

After 90% of its steady state level; the mas of the drug is 90% × 2000

= 0.9 × 2000

= 1800

Hence;

$\mathbf{1800 = 2000 - 2000e^{(-0.015t)}}$

$0.1 = e^{(-0.015t)$

$ln(0.1) = -0.015t$

$t = -\dfrac{In(0.1)}{0.015}$

t = 153.5056729

t ≅ 153.51 minutes

4 0

3 years ago

Kristin owns a bakery called Kristin's Cakes n' Such and is considering lowering the price of her cakes. Kristin polls her custo

azamat

The total revenue that is gained from the sales of the cakes is determined by multiplying the number of cakes by the price. If we let x be the number of $1 that should be deducted from the price and y be the total revenue,
y = (25 - x)(100 + 5x)
Simplifying,
y = 2500 + 25x - 5x²
We get the value of x that will give us the maximum revenue by differentiating the equation and equating the differential to zero.
dy/dx = 0 = 25 - 10x
The value of x is 2.5.
The price of the cake should be 25 - 2.5 = 22.5.
Thus, the price of the cake that will give the maximum potential revenue is $22.5.

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4 years ago

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Anestetic [448]

Answer:

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Step-by-step explanation:

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