The number of weekly hours spent on a smart device varies inversely with the person's age. If a 20-year-old person spends 52 hours on their smart device each week, how many hours does a 50-year-old person spend on their smart device?

Answer:

The answer is:

C. [tex]\bold{x = -1.25h+220}[/tex]

Step-by-step explanation:

Given:

[tex]h=0.8( 220-x )[/tex]

Where [tex]h[/tex] is the heartbeats per minute and

[tex]x[/tex] is the age of person

To find:

Age of person in terms of heartbeats per minute = ?

To choose form the options:

[tex]A.\ x=176-h\\B.\ x=176-0.8h\\C.\ x=-1.25h+220\\D.\ x=h-0.8220[/tex]

Solution:

First of all, let us have a look at the given equation:

[tex]h=0.8( 220-x )[/tex]

It is value of [tex]h[/tex] in terms of [tex]x[/tex].

We have to find the value of [tex]x[/tex] in terms of [tex]h[/tex].

Let us divide the equation by 0.8 on both sides:

[tex]\dfrac{h}{0.8}=\dfrac{0.8( 220-x )}{0.8}\\\Rightarrow \dfrac{1}{0.8}h=220-x\\\Rightarrow 1.25h=220-x[/tex]

Now, subtracting 220 from both sides:

[tex]\Rightarrow 1.25h-220=220-x-220\\\Rightarrow 1.25h-220=-x[/tex]

Now, multiplying with -1 on both sides:

[tex]-1.25h+220=x\\OR\\\bold{x = -1.25h+220}[/tex]

So, the answer is:

C. [tex]\bold{x = -1.25h+220}[/tex]

Answer:

- At any time t, the population is:

P = 375t² + 3000t + 1000

- At time t = 3 days, the population is:

P = 13,375

Step-by-step explanation:

Given the rate of change of the population of bacteria as:

dP/dt = 3000/(1 + 0.25t)

we need to rewrite the given differential equation, and solve.

Rewriting, we have:

dP/3000 = (1 + 0.25t)dt

Integrating both sides, we have

P/3000 = t + (0.25/2)t² + C

P/3000 = t + 0.125t² + C

When t = 0, P = 1000

So,

1000/3000 = C

C = 1/3

Therefore, at any time t, the population is:

P/3000 = 0.125t² + t + 1/3

P = 375t² + 3000t + 1000

At time t = 3 days, the population is :

P = 375(3²) + 3000(3) + 1000

= 3375 + 9000 + 1000

P = 13,375

Answer:

Step-by-step explanation:

Hello, please consider the following.

[tex]x=x(t)=2cos(t)\\\\dx=\dfrac{dx}{dt}dt=x'(t)dt=-2sin(t)dt[/tex]

and

[tex]y=y(t)=2sin(t)\\\\dy=\dfrac{dy}{dt}dt=y'(t)dt=2cos(t)dt[/tex]

Hope this helps.

Do not hesitate if you need further explanation.

Thank you

The values of dx and dy are give as -2sin(t)dt and 2cos(t)dt respectively. The answer to the given problem can be stated as,

dy = 2cos(t)dt

And,  dx = -2sin(t)dt.

The integration can be defined as the inverse operation of differentiation. If a function is the integration of some function f(x) , then differentiation of that function is f(x).

The given integral over C is ∫ (x − y) dx + (x + y) dy.

And, the parameters for C are as follows,

x = 2cos(t)

y = 2sin(t)

0 ≤ t ≤ 2π

Now, on the basis of these parameters dx and dy can be found as follows,

x =  2cos(t)

Differentiate both sides with respect to t as follows,

dx/dt = 2d(cos(t))/dt

=> dx/dt = -2sin(t)

=> dx =  -2sin(t)dt

And, y = 2sin(t)

Differentiate both sides with respect to t as follows,

dy/dt = 2d(sin(t))/dt

=> dy/dt = 2cos(t)

=> dy = 2cos(t)dt

Hence, the value of dx and dy as per the given parameters is -2sin(t)dt and 2cos(t)dt respectively.

To know more about integration click on,

https://brainly.com/question/18125359

#SPJ2

Answer:

The answer is 55, -275, 1375, -6875......

Step-by-step explanation:

Answer:

a≥0

Step-by-step explanation:

a-82≥-82

a≥-82+82

a≥0

Answer:

1/4 of an hour

Step-by-step explanation:

2 divided by 8 = 1/4

Answer:

1/4

Step-by-step explanation:

A whole shift is 8 hours

Part over whole is the fraction

2/8

Divide top and bottom by 2

1/4

Answer:

486

Step-by-step explanation:

Hello!

To find the surface area of a cube we use the equation

[tex]S = 6a^{2}[/tex]

S is the surface area

a is the side length

Put what we know into the equation

[tex]S = 6*9^{2}[/tex]

Solve

S = 6 * 81

S = 486

Hope this Helps!

Answer:486[tex]ft^{2}[/tex]

Step-by-step explanation:

surface area= 6[tex]l^{2}[/tex]

l=9

sa=6 ([tex]9^{2}[/tex])= 6 x 81=486[tex]ft^{2}[/tex]

Answer:

2 sqrt(41) = x

Step-by-step explanation:

This is a right triangle so we can use the Pythagorean theorem

a^2 + b^2 = c^2

8^2 + 10 ^2 = x^2

64+ 100 = x^2

164 = x^2

Take the square root of each side

sqrt(164) = sqrt(x^2)

sqrt(4) sqrt(41) = x

2 sqrt(41) = x

Answer:

2x + 5y + 15

Step-by-step explanation:

add like terms

(x+x) + (y+y)+3y+15

2x+2y+3y+15

2x + 5y + 15

i hope this helps!

Answer:

a

Step-by-step explanation:

answer is a on edg

Aswer:I am sure of the answer it is 6 and 42

Step-by-step explanation:

Answer:

D. There is sufficient information because if two angles and a side included between them are known, the third angle can be determined using the angle sum formula and the remaining two sides can be determined using the law of sines.

Step-by-step explanation:

A triangle is a plane shape that consists of 3 sides and 3 angles. There are different ways of solving for any unknown sides or angles of a triangle.

If any two angles and just one side of a triangle are known, then other angles and sides can also be determined using the sine rule.

For example, if a, b and c are the sides of the triangle and <A, <B and <C are the angles. The sine law is expressed as shown;

a/sinA = b/sinB = c/sinC

Any two can be equated to get any unknown sides and angles.

Also, if two of the angles are known, the third angle can be determined since the sum of angle in a triangle is 180°. If <A and <B are known for example, the third angle <C can be determined using the expression.

<C = 180°-(<A+<B)

Based on the explanation, option D is therefore the correct option i.e There is sufficient information because if two angles and a side included between them are known, the third angle can be determined using the angle sum formula and the remaining two sides can be determined using the law of sines.

Answer:

900

Step-by-step explanation:

You have 10 tens not 1 ten

8 * 100 + 10 * 10 + 0*1

800 + 100 + 0

900

Answer:

[tex]900[/tex]

Step-by-step explanation:

[tex]8 \times 100 + 10 \times 10 + 0 \times 1 \\ 800 + 100 + 0 \\ = 900[/tex]

Answer:

137, 280 feet

Step-by-step explanation:

There are 5,280 feet in a mile.

26 * 5,280 = 137,280

There are 137, 280 feet in 26 miles.

There are 137,280 feet in 26 miles.

The unitary method is a method for solving a problem by the first value of a single unit and then finding the value by multiplying the single value.

We know that there are 5,280 feet in a mile.

So, the solution would be;

26 x 5,280 = 137,280

Thus, There are 137,280 feet in 26 miles.

Learn more about the unitary method;

https://brainly.com/question/23423168

#SPJ2

Answer:

105 years

Step-by-step explanation:

Given the function :

Q(t) = 4e^(-0.00938t)

Q = Quantity in kilogram of an element in a storage unit after t years

how long will it be before the quantity is less than 1.5kg

Inputting Q = 1.5kg into the equation:

1.5 = 4e^(-0.00938t)

Divide both sides by 4

(1.5 / 4) = (4e^(-0.00938t) / 4)

0.375 = e^(-0.00938t)

Take the ln of both sides

In(0.375) = In(e^(-0.00938t))

−0.980829 = -0.00938t

Divide both sides by 0.00938

0.00938t / 0.00938 = 0.980829 /0.00938

t = 104.56599

When t = 104.56599 years , the quantity in kilogram of the element in storage will be exactly 1.5kg

Therefore, when t = 105 years, the quantity of element in storage will be less than 1.5kg

Answer:

Step-by-step explanation:

Using FV = PV(1 + r)^n where FV = future value, PV = present value, r = interest rate per period, and n = # of periods

1/PV (FV) = (PV(1 + r^n)1/PV divide by PV

ln(FV/PV) = ln(1 + r^n) convert to natural log function

ln(FV/PV) = n[ln(1 + r)] by simplifying

n = ln(FV/PV) / ln(1 + r) solve for n

n = ln(2/1) / ln(1 + .08) solve for n, letting FV + 2, PV = 1 and rate = 8% or .08 compound annually

n = 9

n = ln(2/1) / ln(1 + .08/12) solve for n, letting FV + 2, PV = 1 and rate = .08/12 compound monthly

n = 104 months or 8.69 years

n = ln(2/1) / ln(1 + .08/365) solve for n, letting FV + 2, PV = 1 & rate = .08/365 compound daily

n = 3163 days or 8.67 years

Alternatively

A = P e ^(rt)

Given that r = 8%

= 8/100

= 0.08

2 = e^(0.08t)

ln(2)/0.08 = t

0.6931/0.08 = t

t= 8.664yrs

t = 8.67yrs

Which ever approach you choose to use,you will still arrive at the same answer.

Answer:

A

Step-by-step explanation:

The height is always perpinducular to the base. The height here is perpendicular to line segment A.

Answer:

A

Step-by-step explanation:

This sequence converges to 0.

Proof: Recall that

[tex]\displaystyle\lim_{n\to\infty}\frac1{\sqrt n}=0[/tex]

is to say that for any given [tex]\varepsilon>0[/tex], there is some [tex]N[/tex] for which [tex]\left|\frac1{\sqrt n}-0\right|=\frac1{\sqrt n}<\varepsilon[/tex] for all [tex]n>N[/tex].

Let [tex]N=\left\lceil\frac1{\varepsilon^2}\right\rceil[/tex]. Then

[tex]n>\left\lceil\dfrac1{\varepsilon^2}\right\rceil\ge\dfrac1{\varepsilon^2}[/tex]

[tex]\implies\dfrac1n<\varepsilon^2[/tex]

[tex]\implies\dfrac1{\sqrt n}<\varepsilon[/tex]

as required.

Answer:

[tex] \sqrt{4 {}^{2} + ( - 4) {}^{2} } [/tex]

[tex] \sqrt{32} [/tex]

and the angle

[tex] \tan( \alpha ) = - 4 \div 4 = - 1[/tex]

and since the sin component is -ve, we have our angle on 4th quadrant, which equals 315 degrees

Options:

Determine two pairs of polar coordinates for the point (-4, 4) with 0° ≤ θ < 360°. (5 points)

Group of answer choices

(4  , 135°), (-4  , 315°)

(4  , 45°), (-4  , 225°)

(4  , 315°), (-4  , 135°)

(4  , 225°), (-4  , 45°)

Step-by-step explanation:

The guy asking forgot to provide the options you can comment the awnswe in the comments just do it before brainly turns off comments to try and prevent people from learning

Answer:

B) x=80°

Step-by-step explanation:

This is a hexagon, so it has interior angles equaling 720°.  (N-2)*180

So the equation would be

78+134+136+132+2x+x=720

480+3x=720

3x=720-480

3x=240

x=80°

Answer:

Note that orthogonal to the plane means perpendicular to the plane.

Step-by-step explanation:

-1x+3y-3z=1 can also be written as -1x+3y-3z=0

The direction vector of the plane -1x+3y-3z-1=0 is (-1,3,-3).

Let us find a point on this  line for which the vector from this point to (0,0,5) is perpendicular to the given line. The point is x-0,y-0 and z-0 respectively

Therefore, the vector equation is given as:

-1(x-0) + 3(y-0) + -3(z-5) = 0

-x + 3y + (-3z+15) = 0

-x + 3y -3z + 15 = 0

Multiply through by - to get a positive x coordinate to give

x - 3y + 3z - 15 = 0

Answer:

8

Step-by-step explanation:

Ham with or without cheese-2 choices

Bologna with or without cheese-2 choices

Bologna with cheese with water or juice-2 choices

Bologna without cheese with juice or water-2 choices

Ham with cheese with juice or water -2 choices

Ham without cheese with juice or water -2 choices

2+2+2+2=8

Kile has 8 choices for lunch

Answer:

E(w) = 1600000

v(w) = 240000

Step-by-step explanation:

given data

sequence = 1 million iid  (+1 and +2)

probability of transmitting a +1 =  0.4

solution

sequence will be here as

P{Xi = k } = 0.4              for k = +1

                  0.6              for k = +2

and define is

x1  + x2 + ................ + X1000000

so for expected value for W

E(w) = E( x1  + x2 + ................ +  X1000000 )   ......................1

as per the linear probability of expectation

E(w) = 1000000 ( 0.4 × 1 + 0.6 × 2)

E(w) = 1600000

and

for variance of W

v(w) = V ( x1  + x2 + ................ + X1000000 )    ..........................2

v(w) = V x1  + V x2 + ................  + V  X1000000

here also same as that xi are i.e d so cov(xi, xj ) = 0 and i ≠ j

so

v(w) = 1000000 ( v(x) )

v(w) = 1000000 ( 0.24)

v(w) = 240000

Answer:

Surface area of the box = 168 cm²

Step-by-step explanation:

Amount of cardboard needed = Surface area of the box

Since the given box is in the shape of a triangular prism,

Surface area of the prism = 2(surface area of the triangular bases) + Area of the three rectangular lateral sides

Surface area of the triangular base = [tex]\frac{1}{2}(\text{Base})(\text{height})[/tex]

                                                           = [tex]\frac{1}{2}(6)(4)[/tex]

                                                           = 12 cm²

Surface area of the rectangular side with the dimensions of (6cm × 9cm),

= Length × width

= 6 × 9

= 54 cm²

Area of the rectangle with the dimensions (9cm × 5cm),

= 9 × 5

= 45 cm²

Area of the rectangle with the dimensions (9cm × 5cm),

= 9 × 5

= 45 cm²

Surface area of the prism = 2(12) + 54 + 45 + 45

                                           = 24 + 54 + 90

                                           = 168 cm²

Answer:

choice 1,2,4,5 from top to bottom

Step-by-step explanation:

1:the points given are in the line where both planes intersect

2:point H is not on any plane

3:in the diagram point F is on plane R so false

4:if you connect the points given they will intersect so not collinear

5:the points F and G are on the plane R

6:so F is on plane R but H is not on any do false

Answer: x < 28

Step-by-step explanation:

Answer:

Step-by-step explanation:

Hello, first, let's use the product rule.

Derivative of uv is u'v + u v', so it gives:

[tex]f(x)=(x^3-2x+1)(x-3)=u(x) \cdot v(x)\\\\f'(x)=u'(x)v(x)+u(x)v'(x)\\\\ \text{ **** } u(x)=x^3-2x+1 \ \ \ so \ \ \ u'(x)=3x^2-2\\\\\text{ **** } v(x)=x-3 \ \ \ so \ \ \ v'(x)=1\\\\f'(x)=(3x^2-2)(x-3)+(x^3-2x+1)(1)\\\\f'(x)=3x^3-9x^2-2x+6 + x^3-2x+1\\\\\boxed{f'(x)=4x^3-9x^2-4x+7}[/tex]

Now, we distribute the expression of f(x) and find the derivative afterwards.

[tex]f(x)=(x^3-2x+1)(x-3)\\\\=x^4-2x^2+x-3x^3+6x-4\\\\=x^4-3x^3-2x^2+7x-4 \ \ \ so\\ \\\boxed{f'(x)=4x^3-9x^2-4x+7}[/tex]

Hope this helps.

Do not hesitate if you need further explanation.

Thank you

Answer:

[tex]\frac{}{d}[/tex] = −0.26

[tex]s_{d}[/tex] = 0.4219

Step-by-step explanation:

Given:

Sample1:  98.1  98.8  97.3  97.5  97.9

Sample2: 98.7  99.4  97.7  97.1  98.0

Sample 1           Sample 2              Difference d

98.1                        98.7                       -0.6  

98.8                       99.4                       -0.6

97.3                        97.7                       -0.4

97.5                        97.1                         0.4

97.9                        98.0                       -0.1

To find:

Find the values of [tex]\frac{}{d}[/tex] and [tex]s_{d}[/tex]

d overbar ( [tex]\frac{}{d}[/tex])  is the sample mean of the differences which is calculated by dividing the sum of all the values of difference d with the number of values i.e. n = 5

[tex]\frac{}{d}[/tex] = ∑d/n

 = (−0.6 −0.6 −0.4 +0.4 −0.1) / 5

 = −1.3 / 5

[tex]\frac{}{d}[/tex] = −0.26

s Subscript d is the sample standard deviation of the difference which is calculated as following:

[tex]s_{d}[/tex] = √∑([tex]d_{i}[/tex] - [tex]\frac{}{d}[/tex])²/ n-1

[tex]s_{d}[/tex] =

√ [tex](-0.6 - (-0.26))^{2} + (-0.6 - (-0.26))^{2} + (-0.4 - (-0.26))^{2} + (0.4-(-0.26))^{2} + (-0.1 - (-0.26))^{2} / 5-1[/tex]

    =  √ (−0.6 − (−0.26 ))² + (−0.6 − (−0.26))² + (−0.4 − (−0.26))² + (0.4 −  

                                                                     (−0.26))² + (−0.1 − (−0.26))² / 5−1

=  [tex]\sqrt{\frac{0.1156 + 0.1156 + 0.0196 + 0.4356 + 0.0256}{4} }[/tex]

= [tex]\sqrt{\frac{0.712}{4} }[/tex]

= [tex]\sqrt{0.178}[/tex]

= 0.4219

[tex]s_{d}[/tex] = 0.4219

Subscript d ​represent

μ[tex]_{d}[/tex] represents the mean of differences in body temperatures measured at 8 AM and at 12 AM of population.