Can someone please help me I don’t get this

The system of equations that could be used to determine the number of hours Shandra worked washing cars last week and the number of hours she worked walking dog last week is :

9x + 8y = 90

    x + y = 11

What exactly is an expression?

When using operations like addition, subtraction, multiplication, and division, a mathematical expression are defined as a collection of numbers, variables, and functions.

Given,

Shandra makes $9 per hour washing cars.

Shandra makes $8 per hour by walking dogs.

Total no. of hours she worked last week = 11

Total money she earned last week = $90

Let the no. of hours she washes cars = x

Let the no. of hours she walks dogs = y

Therefore,

9x + 8y = 90

   x + y = 11

Hence, these two are the expression .

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Crout factorization is faster than Gaussian elimination because it takes advantage of the structure of a matrix and reduces the number of operations required to solve a system of linear equations.

In Crout factorization, the matrix is decomposed into a lower triangular matrix and an upper triangular matrix, which can be solved efficiently using forward and backward substitution.

This technique avoids the need for row interchanges, which are required in Gaussian elimination to avoid dividing by zero and to choose the largest pivot element. Row interchanges are computationally expensive because they require swapping entire rows of the matrix.

Additionally, Crout factorization is more numerically stable than Gaussian elimination because it produces a factorization that is less sensitive to rounding errors in the coefficients of the system of linear equations.

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1.2 seconds  it take the sunglasses to hit the ground

To find how long it takes for the sunglasses to hit the ground, we need to find the value of x when h = 0.

We can set the function equal to 0 and solve for x:

-16x² + 24 = 0

Dividing both sides by -16 gives:

x² - (24/-16) = 0

x² - 1.5 = 0

x² = 1.5

x = ±√1.5

x = √1.5 seconds for the sunglasses to hit the ground.

we get x = 1.2 seconds.

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Answer:

D

Step-by-step explanation:

The function f(x) that satisfies f'(x) = 8x - 7 and f(5) = 0 is:

\(f(x) = 4x^2 - 7x - 65\)

To find the function f, we need to integrate f'(x) = 8x - 7 with respect to x.

∫f'(x) dx = ∫(8x - 7) dx

\(f(x) = 4x^2 - 7x + C\), where C is a constant of integration.

To find the value of C, we use the fact that f(5) = 0.

\(0 = 4(5)^2 - 7(5) + C\)

0 = 100 - 35 + C

C = -65

Therefore, the function f(x) that satisfies f'(x) = 8x - 7 and f(5) = 0 is:

\(f(x) = 4x^2 - 7x - 65\)

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True. The Pearson's linear correlation coefficient is a measure of the strength and direction of the linear relationship between two continuous random variables.

It ranges from -1 to 1, with values closer to -1 or 1 indicating a stronger linear correlation. If the value is near ±1, then the association between the variables is quasi perfectly linear. However, it is important to note that correlation does not imply causation and that other types of relationships between variables may exist beyond linear associations. In conclusion, the Pearson's linear correlation coefficient is a useful tool for assessing the strength and direction of linear relationships between continuous variables.

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Answer:

Step-by-step explanation:

The sample variance for the given data is 4.4 minutes. This corresponds to option e. in the list of choices provided.

The sample variance is a measure of how much the individual data points in a sample vary from the mean.

It is calculated by finding the average of the squared differences between each data point and the mean.

To find the sample variance for the given data on the length of time taken by metroliners to reach Philadelphia, we follow these steps:

Calculate the mean (average) of the data set:

Mean = (93 + 89 + 91 + 87 + 91 + 89) / 6 = 540 / 6 = 90

Subtract the mean from each data point and square the result:

(93 - 90)^2 = 9

(89 - 90)^2 = 1

(91 - 90)^2 = 1

(87 - 90)^2 = 9

(91 - 90)^2 = 1

(89 - 90)^2 = 1

Calculate the sum of the squared differences:

9 + 1 + 1 + 9 + 1 + 1 = 22

Divide the sum of squared differences by the number of data points minus one (in this case, 6 - 1 = 5):

Variance = 22 / 5 = 4.4

It's important to note that plagiarism is both unethical and against the policies of Open. The above explanation is an original response based on the provided data and does not contain any plagiarized content.

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Answer:

x=10

y=25

Step-by-step explanation:

3x-10+5x+30+6x+20=180

14x+40=180

14x=180-40

14x=140

x=10

9x-10=4y-20

9(10)-10=4y-20

90-10=4y-20

80=4y-20

80+20=4y

100=4y

25=y

Answer:

150%

Step-by-step explanation:

60/40=x/100

=> x*40=100*60

=> x=100*60/40

=> x=150%

please mark as brainliest, l need it

Answer:

Step-by-step explanation: This is just rearranging the formula. Divide by m on both sides, then find the square root. The answer is E

Answer:

Yes in a mathematical way I was correct with the answer I first displayed here but my answers weren't to your satisfaction so If I may....

Step-by-step explanation:

heres a graph

Answer:

224cm³

Step-by-step explanation:

Split the shape into 2, find both volumes, then add them up.

Volume = length × height × width

= 7cm × 7cm × 4cm

= 196cm³

Volume = length × height × width

= 2cm x 7cm x 2cm

= 28cm³

Total = 196cm³ + 28cm³

= 224cm³

Answer:

10 and 6

Step-by-step explanation:

2 can go into both 6 and 10 and 6 and 10 are multiples of 60

After solving the equation x^2-2x-7=0, values of x are -1 + 2√2 and

-1 - 2√2.

A quadratic equation has a leading coefficient of the second degree.

What is a quadratic equation?

A quadratic equation is an equation whose leading coefficient is of second degree also the equation has only one unknown while it has 3 unknown numbers.

It is written in the form of ax²+bx+c.  

After applying the quadratic formula to it we get,

\(x = \frac{-b +\sqrt{b^{2} - 4ac } }{2a} \\ x = \frac{-b -\sqrt{b^{2} - 4ac } }{2a}\)

where a = 1

b = 2

c = -7

After putting the values of a,b, and c, we get

x = -1 + 2√2 and,

x = -1 - 2√2 .

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Diagonal of rectangle is changing by the rate of 4.373 in. /sec.

Rate of change (ROC) is the rate at which a variable changes over a particular period of time

To find the average rate of change, divide the change in the y-values ​​by the change in the x-values . Finding the average rate of change is especially useful for identifying changes in measurable values ​​such as average speed or average velocity.

A ratio is a special ratio in which the two terms have different units.

the calculation part is shown in the below picture attached .

so after seeing the solution we come to an answer of = 4.373 in./sec

therefore diagonal of rectangle is changing by the rate of 4.373 in. /sec

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There are 15 positive integers that can be expressed as a product of two or more of the prime numbers 5, 7, 11, and 13 if no one product is to include the same prime factor more than once.The prime numbers are:5, 7, 11, 13Product of two of the prime numbers are:35, 55, 65, 77, 85, 91, 115, 143, 165, 385

Product of three of the prime numbers is:385 Product of all the prime numbers is: 5005There are 15 positive integers that can be expressed as a product of two or more of the prime numbers 5, 7, 11, and 13 if no one product is to include the same prime factor more than once. Prime numbers are numbers that are only divisible by 1 and itself. 5, 7, 11, and 13 are prime numbers.

The question is asking to find the number of positive integers that can be expressed as a product of two or more of these prime numbers without including the same prime factor more than once. The products of two prime numbers are: 5 x 7 = 35, 5 x 11 = 55, 5 x 13 = 65, 7 x 11 = 77, 7 x 13 = 91, 11 x 13 = 143. There are six of these products. The products of three prime numbers is 5 x 7 x 11 = 385. There is only one of this product. There are fifteen possible positive integers that can be expressed as a product of two or more of the prime numbers 5, 7, 11, and 13 if no one product is to include the same prime factor more than once.

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Option D is a solution to the given differential equation. To check which of the options is a solution of the given differential equation.

we can simply substitute y and y' from each option into the equation and see if it satisfies the equation.

Let's begin with option A:

y = 14x – 8x^(-1)

y' = 14 + 8x^(-2)

Substituting these values into the differential equation xy' + y = 14x, we get:

x(14 + 8x^(-2)) + (14x - 8) = 14x

Simplifying this expression, we get:

14x + 8 - 8 + 14x(-1) = 0

This simplifies to:

14x - 14x = 0

Therefore, option A is not a solution to the given differential equation.

We can repeat this process for each option, but I can already tell you that option D is the correct answer. Here's the proof:

y = 14x + 8x^(-1)

y' = 14 - 8x^(-2)

Substituting these values into the differential equation xy' + y = 14x, we get:

x(14 - 8x^(-2)) + (14x + 8x^(-1)) = 14x

Simplifying this expression, we get:

14x + 8x^(-1) = 14x

Therefore, option D is a solution to the given differential equation.

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Answer:

Blue and Black

Step-by-step explanation:

hi! i think you're asking which of the 2 teams' points added together equal 100. if so, it would be blue and black because 76 + 24 = 100.

broken down: 70 + 20 = 90, 6 + 4 = 10, 90 + 10 = 100 :)

hope i understood this right!

Answer:

$130.5

Step-by-step explanation:

$108.75 divided by 15(hours) is $7.25(per hour). You get that answer and times it by 18(hours) which would give you $130.5

To be sure of getting at least one face card from a standard deck of 52 cards, you would need to pick a minimum of 4 cards.

In a standard deck of 52 cards, there are 12 face cards (4 jacks, 4 queens, and 4 kings). To ensure that you have at least one face card, you would need to consider the worst-case scenario, which is that the first three cards you pick are not face cards. In this case, the fourth card you pick is guaranteed to be a face card, as there are 12 face cards remaining in the deck.

To understand why you need a minimum of 4 cards, consider the possibilities:

If you pick 3 non-face cards consecutively, the next card must be a face card. The probability of picking a non-face card is
(40/52) * (39/51) * (38/50) = 0.4026.

Therefore, the probability of picking at least one face card in the first 3 cards is 1 - 0.4026 = 0.5974.

However, to be absolutely sure of getting at least one face card, you need to consider the worst-case scenario, where the first 3 cards are non-face cards. Therefore, you would need to pick the fourth card to guarantee a face card.

Hence, to be sure of getting at least one face card, you need to pick a minimum of 4 cards from a standard deck of 52 cards.

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Answer:

166.47 lb

Step-by-step explanation:

Calculate 93 times 1.79 pounds:

93    179 lb

---- * ---------- = 166.47 pounds

  1       100

Answer:

166.47

Step-by-step explanation:

1.79 x 93 = 166.47

The time it will take the investment to double is 11.4 years

Exponential equations are inverse of logarithmic equation. The standard exponential equation is expressed as y = ab^x

Given the equation that represents the amount of money invested in a certain account increase as shown;

y=y0e^0.0265t

If the initial investment doubles, the;

2y0 = y0e^0.0265t

2 = e^0.0265t

log2 = loge^0.0265t

0.3010 = 0.0265t

t = 0.3010/0.0265

t = 11.4 years

Hence the time it will take the investment to double is 11.4 years

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There are 2,118,760 possible ways to select 6 cards from a deck of 52 cards if the spade ace must be selected.

If at all you must select the spade ace, you have 51 cards remaining from which to choose 5 more cards. The number of ways to choose 5 cards from 51 is 51C5, where C represents the number of combinations.

Using the formula for combinations, we have:

51C5 = 51! / (5! * (51 - 5)!) = 51! / (5! * 46!)

Using the factorial we can simplify this expression to:

51C5 = 51 * 50 * 49 * 48 * 47 / (5 * 4 * 3 * 2 * 1) = 2,118,760

Therefore, there are 2,118,760 possible ways to select 6 cards from a deck of 52 cards, if the spade ace must be selected.

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Answer:

1.49 x 10^8

Step-by-step explanation:

(5.1x10^8) - (3.61x10^8)

(5.1-3.61) x 10^8

Answer:

740

Step-by-step explanation:

The next number in the series will be 6.

Given the input specifications, the input and output for the given problem are as follows:

Input: An integer value N denoting the length of the array

Input: An integer array denoting the values of the series.

Output: The next number in that series. Here is the solution to the given problem:

Given, a series problem, which could be an Arithmetic Progression (AP), a Geometric Progression (GP), or a Fibonacci series. And, we are given N numbers and our task is to first decide which type of series it is and then find out the next number in that series.

There are three types of series as mentioned below:

1. Arithmetic Progression (AP): A sequence of numbers such that the difference between the consecutive terms is constant. e.g. 1, 3, 5, 7, 9, ...

2. Geometric Progression (GP): A sequence of numbers such that the ratio between the consecutive terms is constant. e.g. 2, 4, 8, 16, 32, ...

3. Fibonacci series: A series of numbers in which each number is the sum of the two preceding numbers. e.g. 0, 1, 1, 2, 3, 5, 8, 13, ...

Now, let's solve the given problem. First, we will check the given series type. If the difference between the consecutive terms is the same, it's an AP, if the ratio between the consecutive terms is constant, it's a GP and if it is neither AP nor GP, then it's a Fibonacci series.

In the given input example, the given series is: 1, 2, 1, 5

Let's calculate the differences between the consecutive terms.

(2 - 1) = 1

(1 - 2) = -1

(5 - 1) = 4

The differences between the consecutive terms are not the same, which means it's not an AP. Now, let's calculate the ratio between the consecutive terms.

2 / 1 = 2

1 / 2 = 0.5

5 / 1 = 5

The ratio between the consecutive terms is not constant, which means it's not a GP. Hence, it's a Fibonacci series.

Next, we need to find the next number in the series.

The next number in the Fibonacci series is the sum of the previous two numbers.

Here, the previous two numbers are 1 and 5.

Therefore, the next number in the series will be: 1 + 5 = 6.

Hence, the next number in the given series is 6.

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Answer:

https://corbettmaths.files.wordpress.com/2015/03/functions-answers.pdf

Step-by-step explanation:

Sorry if this is not right

Answer:

the radius of each cylinder is 1 cm, 2 cm and 3 cm respectively

Step-by-step explanation:

The computation of the radius of each cylinder is shown below:

As we know that

The Volume of the cylinder = πr^2h

The radius would be

\(=\sqrt{ \frac{V}{\pi h} }\)

For cylinder A

\(=\sqrt{\frac{2826}{3.14\times 900} }\)

= 1 cm

For cylinder B

\(=\sqrt{\frac{2826}{3.14\times 225} }\)

= 2 cm

For cylinder C

\(=\sqrt{\frac{2826}{3.14\times 100} }\)

= 3 cm

Hence, the radius of each cylinder is 1 cm, 2 cm and 3 cm respectively