What is 21/56 and 63/81 in simplest form

Which link would provide the best supporting information for this piece?

konstantin123 [22]

Answer: A

Step-by-step explanation:

8 0

3 years ago

-x -7y = 14<br> -4x -14y =28

koban [17]

Given:

$\to \bold{-x -7y = 14}\\\\\to \bold{-4x -14y =28}\\\\$

To find:

$\bold{x \ and \ y}=?$

Solution:

$\to \bold{-x -7y = 14}..................... (i) \\\\\to \bold{-4x -14y =28} .................(ii)\\\\$

Solving the equation (i):

$\to \bold{-x -7y = 14} \\\\ \to \bold{-x= 14+7y} \\\\ \to \bold{x= - (14+7y)} \\\\$

Putting the value of x into the equation (ii):

$\to \bold{-4(-(14+7y)) -14y =28} \\\\\to \bold{4(14+7y) -14y =28} \\\\\to \bold{56+28y -14y =28} \\\\\to \bold{56+14y =28} \\\\\to \bold{28+14y =0} \\\\\to \bold{14y =-28} \\\\\to \bold{y =\frac{-28}{14}} \\\\\to \bold{y =-2} \\\\$

Putting the value of y into the equation (i):

$\to \bold{-x -7(-2) = 14}\\\\\to \bold{-x +14 = 14}\\\\\to \bold{-x = 14-14}\\\\\to \bold{x = 0}\\\\$

So, the value of $\bold{x=0 \ and\ y= -2}\\\\$

Learn more:

brainly.com/question/10151402

7 0

3 years ago

A barber has already cut for peoples hair today. Every 10 minutes another person comes to the Barber to get a haircut. Write

Alexeev081 [22]

Answer:

Ans. (1) For preparing vaccines, in olden days,microbes were injected in the bodies of horses ormonkeys. These laboratory animals used to makeantibodies to defend these microbes. Antibodies areproteins which can act against the disease-causinggerms. These antibodies were extracted from theblood of these animals and were used as vaccines.(2) Now-a-days with the advent of biotechnology,the vaccines are manufactured in laboratories withthe help of bacteria. For this purpose, a detailedstudy of the disease causing germ is undertaken.The genes and the DNA of such microbes arethoroughly explored. Then based on thisinformation, proteins which can act against suchmicrobes are synthetically prepared in thelaboratories. The safe vaccine is produced in such away which can defend the body against infections.3) Some types of vaccines are prepared from theextracts of germs. These germs or microbes aredeactivated and made dormant. When they areinjected in the body of a person, they initiate thedefending action. The body of such vaccinatedperson, already develops the antibodies in his or herbody. When in future, this person is again attackedby similar germs the defence starts immediately andthe person does not become sick.

7 0

3 years ago

State University uses thousands of fluorescent light bulbs each year. The brand of bulb it currently uses has a mean life of 600

Ipatiy [6.2K]

Answer:

The test statistic is t = 2.5.

The p-value of the test is of 0.007 < 0.05, which means that the evidence supports the manufacturer's claim at the .05 significance level.

Step-by-step explanation:

Mean life of 600 hours. Test if it is more.

At the null hypothesis, we test if the mean is of 600 hours, that is:

$H_0: \mu = 600$

At the alternative hypothesis, we test if the mean is of more than 600 hours, that is:

$H_1: \mu > 600$

The test statistic is:

$t = \frac{X - \mu}{\frac{s}{\sqrt{n}}}$

In which X is the sample mean, $\mu$ is the value tested at the null hypothesis, s is the standard deviation and n is the size of the sample.

600 is tested at the null hypothesis:

This means that $\mu = 600$

Suppose 100 bulbs were tested and found to have a mean of 625 hours with a standard deviation of 100.

This means that $n = 100, X = 625, s = 100$ .

Value of the test-statistic:

$t = \frac{X - \mu}{\frac{s}{\sqrt{n}}}$

$t = \frac{625 - 600}{\frac{100}{\sqrt{100}}}$

$t = 2.5$

The test statistic is t = 2.5.

P-value of the test and decision:

The p-value of the test is the probability of finding a sample mean above 625 hours, which is a right-tailed test, with t = 2.5 and 100 - 1 = 99 degrees of freedom.

Using a t-distribution calculator, this p-value is of 0.007.

The p-value of the test is of 0.007 < 0.05, which means that the evidence supports the manufacturer's claim at the .05 significance level.

4 0

3 years ago

I m s o d u m b t h a t i c a n t e v e n d o 1 + 1 s o i n e e d h e l p

Ber [7]

Answer:

1 + 1 = 2

Step-by-step explanation:

:)

6 0

3 years ago

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