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3 years ago

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Which pair shows equivalent expressions?

2 answers:

Dmitry_Shevchenko [17]3 years ago

8 0

Which pair shows equivalent expressions?

A.2(2/5x + 2)=2 2/5x + 1

B.2(2/5x + 2)=4/5x + 4

C.2(2/5x + 4)=4/5x + 2

D.2(2/5x + 4)=2 2/5x + 8

Solution:

$2(\frac{2}{5}x + 2)$

Let us distribute 2 inside the parenthesis.

That is, we use distributive property:

a(b+c)=ab+ac

$2(\frac{2}{5}x + 2) =\frac{2*2}{5}x+2*2$

So, $2(\frac{2}{5}x + 2) =\frac{4}{5}x+4$

Answer:Option (b)

$2(\frac{2}{5}x+4)$

Applying distributive property, a(b+c)=ab+ac

$2(\frac{2}{5}x+4) =2*\frac{2}{5} x+2*4$

$2(\frac{2}{5}x+4) =\frac{2*2}{5} x+2*4$

$2(\frac{2}{5}x+4) =\frac{4}{5} x+8$

So, Option (B) is correct.

Sindrei [870]3 years ago

6 0

Answer:

So, Option (B) is correct.

Step-by-step explanation:

did it

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Kwamee created a coffee blend for his cafe by mixing Kona beans and Fuji beans. Kona beans cost $11 per pound and Fuji beans cos

yKpoI14uk [10]

Let's use K for Kona and F for Fuji. The system of equations has to be a balanced system. For example, you can't mix the number of pounds of beans with the cost for each because pounds and dollars are different and you can only combine like terms...pounds with pounds and dollars with dollars. So let's start with the number of pounds. Since we don't know how much of each he bought we have the 2 unknowns, F and K, but we DO know that he bought 23 pounds total. So the first equation is
K + F = 23
Now let's see what we can do with the dollars. Again, we don't know how much he bought of each kind of coffee, but we do know that Kona beans cost $11 per pound and that Fuji beans cost $7.50 per pound, and we know that he spent a total of $197. So let's set that up:
11K + 7.50F = 197
Those are your 2 equations. It doesn't say you need to solve them, so you're done.

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2 years ago

Over the last 2.5 years, the water level in a lake has changed by -0.3 feet per year. Scientists predict that the water level wi

klio [65]

Answer:

Step-by-step explanation:

A)

"In the last 2.5 years, the water level has decreased 0.75 feet."

In the very first statement it has been stated that over the last 2.5 years, the water level in a lake has changed by -0.3 feet per year. That means in the last 2.5 years , total decrease in level is as follows

2.5 x - 0.3 = - .75 ft .

So the statement is true.

B)

"The overall change of the water level after 7.5 years will be -2.75 feet."

This statement appears to be false based on information provided

No prediction regarding rate of decrease for a period beyond 5 year has been made so any statement with respect to a timeline of 7.5 years may turn out to be false.

C)

"The change in water level each year for the next 5 years will be -0.4 feet. "

This statement prima-facie appears to be true because rate of decrease stated in the statement is 0.4 ft /year for next 5 years .

D )

"The overall change in water level for the next 5 years is equal to 5(0.4)"

this statement is true

as change in one year = .4

change in 5 years = 5 x .4

5 0

2 years ago

A standard deck of cards contains 52 cards. The cards have 4 different suits: clubs, diamonds, hearts, and spades. For each suit

Taya2010 [7]

Answer:

a. 108336, b. 480200

Step-by-step explanation:

a. No. of ace cards = 4

No. of non ace cards= 48

We draw 5 cards

So,

No. of ways of 2 aces = C(4,2) C(48,3)

No. of ways of 3 aces = C(4,3) C(48,2)

No. of ways of 4 aces = C(4,4) C(48,1)

Hence

No. of ways of 2 or more aces

= C(4,2) + C(48,3) + C(48,3) + C(4,3)C(48,2) +C(4,4)C(48,1)

= 6(17296) + 4(1128) + (48)

= 108336

b. No of ways any 5 cards can be chosen = C(52,5)

No. of ways kings of diamonds or queen of hearts is chosen = C(50,5)

Hence

No. of ways of choosing king of diamonds, queen of hearts or both = C(52,5) – C(50,5)

= 480200

4 0

2 years ago

Is it right? ... i will give brainliest

NeTakaya

Answer:

yes ur right!

Step-by-step explanation:

5 0

3 years ago

Read 2 more answers

Darren wants to estimate the mean age in a population of trees. He'll sample nnn trees and build a 90\%90%90, percent confidence

Alchen [17]

Using the z-distribution, as we have the standard deviation for the population, it is found that the smallest sample size required to obtain the desired margin of error is of 77.

<h3>What is a z-distribution confidence interval?</h3>

The confidence interval is:

$\overline{x} \pm z\frac{\sigma}{\sqrt{n}}$

In which:

$\overline{x}$ is the sample mean.

z is the critical value.

n is the sample size.

$\sigma$ is the standard deviation for the population.

The margin of error is given by:

$M = z\frac{\sigma}{\sqrt{n}}$

In this problem, we have that the parameters are given as follows:

$M = 3, z = 1.645, \sigma = 16$ .

Hence, solving for n, we find the sample size.

$M = z\frac{\sigma}{\sqrt{n}}$

$3 = 1.645\frac{16}{\sqrt{n}}$

$3\sqrt{n} = 1.645 \times 16$

$\sqrt{n} = \frac{1.645 \times 16}{3}$

$(\sqrt{n})^2 = \left(\frac{1.645 \times 16}{3}\right)^2$

$n = 76.97$

Rounding up, the smallest sample size required to obtain the desired margin of error is of 77.

More can be learned about the z-distribution at brainly.com/question/25890103

4 0

1 year ago