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2 years ago

What is the value of 81x2y3+z if x=3 y=4 and z=19

1 answer:

3 0

Ok first of all I am assuming you mean

81.(x**2).(y**3) +z = Value

We just need to simply substitute x , y and z

81.(3*3)(4*4*4) +19 = Value

46656 + 19 = Value..............>> Value = 46675

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Jennifer has 12 nickels and dimes. The value of her coins is $1

ELEN [110]

Answer:

One Dollar and 80 cents.

Step-by-step explanation:

12 x 5 is 60. The amount of nickles multiplied by the value of one nickel which is 5 cents. Then you take the value of a dime and multiply it by the amount of dimes, 12. You get 120. Add 60 to 120 and you get 180. One Dollar is 100 cents, add 80 to 100 and you get one Dollar and 80 cents.

3 0

2 years ago

Bernard solved the equation 5x+(-4)=6x+4 using algebra tiles. Which explains why Bernard added 5 negative x-tiles to both sides

densk [106]

A) He wanted to create zero pairs on the left side of the equation to get a positive coefficient of x on the right side

7 0

2 years ago

Read 2 more answers

A student has to take two quizzes tomorrow. He has only enough time to study for one of them. The history quiz has 5 true or fal

nalin [4]

Answer:

Answer:

Option B is correct.

Miguel should study for the Science quiz as he will do worse in that quiz by guessing.

Step-by-step explanation:

Miguel has to take two quizzes

1) 4 true or false questions on History with a 0.5 chance of acing the quiz

Expected number of correct questions = np

n = number of questions

p = probability of acing the test

Expected number of correct questions = 4 × 0.5 = 2

2) 3 multiple choice questions on Science with a 0.2 chance of acing the quiz.

Expected number of correct questions = 0.2 × 3 = 0.6

It is evident that guessing would yield a worse result in the Science quiz with less than 1 question expected to be correct than history, where he is still expected to get 2 questions correctly by guessing.

6 0

2 years ago

Read 2 more answers

A cardboard box without a lid is to have a volume of 16,384 cm3. Find the dimensions that minimize the amount of cardboard used.

Reika [66]

Answer:

The dimensions that minimize the amount of cardboard used is

x = 31 cm , y = 34 cm & Z = 15.54 cm

Step-by-step explanation:

Volume of the cardboard = 16,384 $cm^{3}$

The function that represents the area of the cardboard without a lid is given by

$f (x,y,z) = xy + 2xz + 2yz$ ------ (1)

Volume of the cardboard with sides x, y & z is

$xyz = 16384$

$z = \frac{16384}{xy}$

Put this value of z in equation (1) we get

$f (x,y,z) = xy + 2x(\frac{16384}{xy} ) + 2y(\frac{16384}{xy} )$

$f (x,y,z) = xy + \frac{32768}{y} + 2y(\frac{32768}{x} )$

Differentiate above equation with respect to x & y we get

$f_{x} = y - \frac{32768}{x^{2} }$

$f_{y} = x - \frac{32768}{y^{2} }$

Take $f_{x} = 0 \ and \ f_{y} = 0$

$y - \frac{32768}{x^{2} } = 0$

$y = 32768 \ x^{-2}$ ------ (2)

$x - \frac{32768}{y^{2} } = 0$

$x = 32768 \ y^{-2}$ ------- (3)

By solving equation (2) & (3) we get

$x^{3} = 32768$

x = 31 cm

From equation 2

$y = 32768 \ x^{-2}$

y = 32768 ( $31^{-2}$ )

y = 34 cm

$z = \frac{16384}{xy}$

$z = \frac{16384}{(34)(31)}$

Z = 15.54 cm

Thus the dimensions that minimize the amount of cardboard used is

x = 31 cm , y = 34 cm & Z = 15.54 cm

6 0

2 years ago

The population p of a small community on the outskirts of a city grows rapidly over a 20-year period: t05101520p1002004509502000

myrzilka [38]

Answer:

The population of the small community, 5 years into the future, after the initial 20-year period = 4268.

Step-by-step explanation:

t | 0 | 5 | 10 | 15 | 20

p | 100 | 200 | 450 | 950 | 2000

The exponential function will look like

p = aeᵏᵗ

where a and k are constants.

Take the natural logarithms of both sides

In p = In aeᵏᵗ

In p = In a + In eᵏᵗ

In p = In a + kt

In p = kt + In a.

We then use linear regression to fit the data of In p against t to obtain k and In a.

t | 0 | 5 | 10 | 15 | 20

p | 100 | 200 | 450 | 950 | 2000

In p | 4.605 | 5.298 | 6.109 | 6.856 | 7.601

In p = kt + In a.

y = mx + b

m = k and b = In a

Performing a linear regression analysis on the now-linear relationship between In p and t and also plotting a graph of the variables.

The regression equation obtained is

y = 0.151x + 4.584

The first attached image shows the equations necessary for the estimation of the linear regression parameters.

The second attached image shows the use of regression calculator and the plot of the function In p versus t.

Comparing

y = 0.151x + 4.584

With

In p = kt + In a.

y = In p

k = 0.151

x = t

In a = 4.584

a = 97.905

The exponential function relating p and t,

p = aeᵏᵗ now becomes

p = 97.905 e⁰•¹⁵¹ᵗ

So, to predict the population 5 years into the future, that is 5 years after the 20 year period.

we need p at t=25 years.

0.151 × 25 = 3.775

p(t=25) = 97.905 e³•⁷⁷⁵ = 4268.41 = 4268.

Hope this Helps!!!

7 0

2 years ago