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3 years ago

Help on this please!

Mathematics

1 answer:

Nana76 [90]3 years ago

8 0

2/9 - 7/12

First, multiply to find a common denominator. Multiply both pieces of the left fraction by 12, and both pieces of the right fraction by 9.

24/108 - 63/108 = -39/108 = -13/36

a= -13
b= 36

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You need to purchase centerpieces for no more than 12 tables at Prom. There is a

Lera25 [3.4K]

Answer:

{f + c < 12

{7c + 4f < 100

-5⅓ < f

7⅓ > c

Step-by-step explanation:

The keyphrase is no more than, which tells you that the inequality symbol has to be less than.

I am joyous to assist you anytime.

3 0

3 years ago

A particle moving in a planar force field has a position vector x that satisfies x'=Ax. The 2×2 matrix A has eigenvalues 4 and 2

andrey2020 [161]

Answer:

The required position of the particle at time t is: $x(t)=\begin{bmatrix}-7.5e^{4t}+1.5e^{2t}\\2.5e^{4t}-1.5e^{2t}\end{bmatrix}$

Step-by-step explanation:

Consider the provided matrix.

$v_1=\begin{bmatrix}-3\\1 \end{bmatrix}$

$v_2=\begin{bmatrix}-1\\1 \end{bmatrix}$

$\lambda_1=4, \lambda_2=2$

The general solution of the equation $x'=Ax$

$x(t)=c_1v_1e^{\lambda_1t}+c_2v_2e^{\lambda_2t}$

Substitute the respective values we get:

$x(t)=c_1\begin{bmatrix}-3\\1 \end{bmatrix}e^{4t}+c_2\begin{bmatrix}-1\\1 \end{bmatrix}e^{2t}$

$x(t)=\begin{bmatrix}-3c_1e^{4t}-c_2e^{2t}\\c_1e^{4t}+c_2e^{2t} \end{bmatrix}$

Substitute initial condition $x(0)=\begin{bmatrix}-6\\1 \end{bmatrix}$

$\begin{bmatrix}-3c_1-c_2\\c_1+c_2 \end{bmatrix}=\begin{bmatrix}-6\\1 \end{bmatrix}$

Reduce matrix to reduced row echelon form.

$\begin{bmatrix} 1& 0 & \frac{5}{2}\\ 0& 1 & \frac{-3}{2}\end{bmatrix}$

Therefore, $c_1=2.5,c_2=1.5$

Thus, the general solution of the equation $x'=Ax$

$x(t)=2.5\begin{bmatrix}-3\\1\end{bmatrix}e^{4t}-1.5\begin{bmatrix}-1\\1 \end{bmatrix}e^{2t}$

$x(t)=\begin{bmatrix}-7.5e^{4t}+1.5e^{2t}\\2.5e^{4t}-1.5e^{2t}\end{bmatrix}$

The required position of the particle at time t is: $x(t)=\begin{bmatrix}-7.5e^{4t}+1.5e^{2t}\\2.5e^{4t}-1.5e^{2t}\end{bmatrix}$

6 0

3 years ago

In the following hypothetical scenarios, classify each of the specified numbers as a parameter or a statistic.

soldi70 [24.7K]

Answer:

Explained below.

Step-by-step explanation:

A parameter is a valuable element of statistical analysis. It denotes the characteristics that are used to define a given population. It is used to define a particular attribute of the population. For instance, population mean, population standard deviation, population proportion and so on.

While making a statistical conclusion about the population under study, the parameter value is unknown. This is because it would not be possible to gather data from every single member of the population. So a sample is selected from the population to derive a conclusion about the parameter.

A statistic is the value of the characteristics that are computed using this sample. For instance, sample mean, sample standard deviation, sample proportion and so on.

(a)

There have been 44 Presidents of the United States, and 36% of them were Democrats. The 36% here is a parameter.

(b)

In a 2015 Gallup poll of 1025 adults living in the United States, 53% said they trust the judicial branch of the federal government. The 53% here is a statistic.

(c)

The survey results from 12 local parks show the mean height of 60 ft for mature oak trees. The mean height of 60 ft is a statistic.

(d)

The 72 employees at ABC company have a mean income of $52,317 with a standard deviation of $36,829. The $36,829 is a parameter.

(e)

In a random sample of homeowners in the United States, it is found that 34% of the sampled homeowners renew their home warranty. The 34% here is a statistic.

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3 years ago

A submarine was located 200 feet below sea level. If it ascends 55 feet and then drops 87 feet, then which integer represents th

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Answer:

-232

Step-by-step explanation:

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3 years ago

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