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3 years ago

X + y + z = 7 2x − y + z = 7 3x − z = 2

1 answer:

7 0

A) X + y + z = 7
B) 2x − y + z = 7

C) 3x − z = 2
C) z = 3x -2 Substituting this into equations A) and B)


A) X + y + 3x -2 = 7
B) 2x − y + 3x -2 = 7 Adding A and B
3x + 6x -4 = 14
9x = 18
x = 2
Since x = 2 then
A) 2 + y + 6 -2 = 7
A) y = 1

A) X + y + z = 7
A) 2 + 1 + z = 7
z = 4

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Natalie just invited 100 guests to a party in her small house. The base of her house is a rectangle with dimensions 8m by 16m. I

Alex787 [66]

Answer:

6 units by 12 units

Step-by-step explanation:

Since the measurements in meters are multiples of 4, it makes this problem a little easier.

First you divide 8 by 4 to get 2

Then divide 16 by 4 to get 4

After that you're going to multiply 3 units by both quotients separately.

So you multiply 3 by 2 to get 6

Then you multiply 3 by 4 to get 12

So then you end up with a 6 unit by 12 unit drawing.

It's funny because I was actually looking for the answer to this problem. Sorry I was a little late

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3 years ago

Deborah has two paintings in her portfolio and paints three more each week.Kai has twelve paintings in her portfolio and paints

elena-14-01-66 [18.8K]

Well, we can set up these equations like this-
Deborah- 2+3w
Kai- 12+2w
w=number of weeks that pass
Now, we set them equal to each other:
2+3w=12+2w

Solve for w
2-12=2w-3w
-10 = -1w
w = 10
10 weeks. Hope this helped!

4 0

3 years ago

Can you help me round 3,418,913 to the nearest thousand

Kamila [148]

3,419,000 because the 913 rounds the number up

6 0

3 years ago

Read 2 more answers

What is the fuction for the graph?

Andrews [41]

The piecewise defined function is formed by the following three functions: y = 40, for 0 ≤ x < 15, y = 0.0425 · x² - 3.8 · x + 87.438, for 15 ≤ x < 65 and y = 0.4 · x - 6, for x ≥ 65.

<h3>What is the piecewise defined function behind the graph?</h3>

In this problem we have a piecewise defined function formed by three functions: (i) Linear equation, (ii) Quadratic equation, (iii) Linear equation. The first function is y = 40, for 0 ≤ x < 15.

The second function can be found based on the knowledge of three points:

y = a · x² + b · x + c

(x₁, y₁) = (15, 40)

40 = 225 · a + 15 · b + c

(x₂, y₂) = (45, 2.5)

2.5 = 2025 · a + 45 · b + c

(x₃, y₃) = (65, 20)

20 = 4225 · a + 65 · b + c

And the quadratic equation is y = 0.0425 · x² - 3.8 · x + 87.438, for 15 ≤ x < 65.

And the latter linear equation is:

y = m · x + b

m = (30 - 20)/(90 - 65)

m = 0.4

And the x-intercept is:

b = y - m · x

b = 20 - 0.4 · 65

b = - 6

The linear equation is y = 0.4 · x - 6, for x ≥ 65.

To learn more on piecewise defined functions: brainly.com/question/12561612

#SPJ1

7 0

1 year ago

A company surveyed 2400 men where 1248 of the men identified themselves as the primary grocery shopper in their household. a) E

polet [3.4K]

Answer:

a) With a confidence level of 98%, the percentage of all males who identify themselves as the primary grocery shopper are between 0.4962 and 0.5438.

b) The lower limit of the confidence interval is higher that 0.43, so if he conduct a hypothesis test, he will find that the data shows evidence to said that the fraction is higher than 43%.

c) $\alpha =1-0.98=0.02$

Step-by-step explanation:

If np' and n(1-p') are higher than 5, a confidence interval for the proportion is calculated as:

$p'-z_{\alpha/2}\sqrt{\frac{p'(1-p')}{n} }\leq p\leq p'+z_{\alpha/2}\sqrt{\frac{p'(1-p')}{n} }$

Where p' is the proportion of the sample, n is the size of the sample, p is the proportion of the population and $z_{\alpha/2}$ is the z-value that let a probability of $\alpha/2$ on the right tail.

Then, a 98% confidence interval for the percentage of all males who identify themselves as the primary grocery shopper can be calculated replacing p' by 0.52, n by 2400, $\alpha$ by 0.02 and $z_{\alpha/2}$ by 2.33

Where p' and $\alpha$ are calculated as:

$p' = \frac{1248}{2400}=0.52\\\alpha =1-0.98=0.02$

So, replacing the values we get:

$0.52-2.33\sqrt{\frac{0.52(1-0.52)}{2400} }\leq p\leq 0.52+2.33\sqrt{\frac{0.52(1-0.52)}{2400} }\\0.52-0.0238\leq p\leq 0.52+0.0238\\0.4962\leq p\leq 0.5438$

With a confidence level of 98%, the percentage of all males who identify themselves as the primary grocery shopper are between 0.4962 and 0.5438.

The lower limit of the confidence interval is higher that 0.43, so if he conduct a hypothesis test, he will find that the data shows evidence to said that the fraction is higher than 43%.

Finally, the level of significance is the probability to reject the null hypothesis given that the null hypothesis is true. It is also the complement of the level of confidence. So, if we create a 98% confidence interval, the level of confidence $1-\alpha$ is equal to 98%

It means the the level of significance $\alpha$ is:

$\alpha =1-0.98=0.02$

4 0

2 years ago