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3 years ago

16 POINTS

1 answer:

8 0

Solve the following system using elimination:
{7 x + 2 y = -19 | (equation 1)
{2 y - x = 21 | (equation 2)

Add 1/7 × (equation 1) to equation 2:
{7 x + 2 y = -19 | (equation 1)
{0 x+(16 y)/7 = 128/7 | (equation 2)

Multiply equation 2 by 7/16:
{7 x + 2 y = -19 | (equation 1)
{0 x+y = 8 | (equation 2)

Subtract 2 × (equation 2) from equation 1:
{7 x+0 y = -35 | (equation 1)
{0 x+y = 8 | (equation 2)

Divide equation 1 by 7:
{x+0 y = -5 | (equation 1)
{0 x+y = 8 | (equation 2)

Collect results:
Answer: {x = -5, y = 8

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Solve the proportion of 2/v = 4/6

dsp73

$\dfrac{2}{v} = \dfrac{4}{6}$

Cross multiply:
$4v = 12$

Divide both sides by 4:
$v = 3$

3 0

2 years ago

Eight less than four times the quantity of five more than twice a number is 36 what is the number

OleMash [197]

4(2x+5)-8 = 36
8x+20-8 = 36
8x = 24
x = 3

5 0

2 years ago

She is serving hot coffee and cold coffee in two rectangular-shaped tanks, each with dimensions width 8.75 inches, length 8.75 i

Blababa [14]

The volume of the coffee in each tank will be 1760. in³. The mass of cold coffee and hot coffee will be 6163.29 oz and 10213.45 oz. Then the number of the tank placed on a table is one only.

<h3>How to find the density and volume?</h3>

She is serving hot coffee and cold coffee in two rectangular-shaped tanks, each with dimensions width of 8.75 inches, a length of 8.75 inches, and a height of 23 inches.

The hot coffee has a density of 5.8 oz/in³ and the cold coffee has a density of 3.5 oz/ in³.

Then the volume of the coffee in each tank will be

We know that the dimension of both tanks is equal. Then the volume will remains equal.

Volume = L × B × H

Volume = 8.75 × 8.75 × 23

Volume = 1760.9375 ≅ 1760.94 in³

Then the mass of the coffee in each the tank will be

The mass of hot coffee will be

Mass = Density × Volume

Mass = 5.8 × 1760.94

Mass = 10213.45 oz

The mass of cold coffee will be

Mass = Density × Volume

Mass = 3.5 × 1760.94

Mass = 6163.29 oz

Then the number of the tank placed on a table is one only.

More about the density and volume link is given below.

brainly.com/question/952755

#SPJ1

3 0

2 years ago

A consumer survey indicates that the average household spendsμ= $185on groceries each week. The distribution of spending amounts

Vitek1552 [10]

Answer:

$P(X>200)=P(\frac{X-\mu}{\sigma}>\frac{200-\mu}{\sigma})=P(Z>\frac{200-185}{25})=P(Z>0.6)$

And we can find this probability using the complement rule and with the normal standard table or excel:

$P(Z>0.6)=1-P(z$

Step-by-step explanation:

Previous concepts

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".

Solution to the problem

Let X the random variable that represent the average household spent of a population, and for this case we know the distribution for X is given by:

$X \sim N(185,25)$

Where $\mu=185$ and $\sigma=25$

We are interested on this probability

$P(X>200)$

And the best way to solve this problem is using the normal standard distribution and the z score given by:

$z=\frac{x-\mu}{\sigma}$

If we apply this formula to our probability we got this:

$P(X>200)=P(\frac{X-\mu}{\sigma}>\frac{200-\mu}{\sigma})=P(Z>\frac{200-185}{25})=P(Z>0.6)$

And we can find this probability using the complement rule and with the normal standard table or excel:

$P(Z>0.6)=1-P(z$

7 0

3 years ago

What happens to the mean of the data set {2, 4, 5, 6, 8, 2, 5, 6} if the number 7 is added to the data set?

konstantin123 [22]

Answer:

It increases

Step-by-step explanation:

The mean of the given data set of 8 values is 4.75 ( $\frac{2+4+5+6+8+2+5+6}{8}$ )

Adding 7 into the data set also increase the number of data points to 9, so the mean becomes: $\frac{2+4+5+6+8+2+5+6+7}{9}$ , which is equal to 5

Hope this helps

7 0

2 years ago