All categories

3 years ago

What two numbers multiply to 10 and add to 9

Mathematics

1 answer:

sveta [45]3 years ago

8 0

Did you mean -10? If so that is -1 and 10. 10 and 9 is not possible to answer.
-1+10=9
-1*10=-10

You might be interested in

Find A. Round to the nearest tenth.

Marianna [84]

Answer:

27.8 degrees

Step-by-step explanation:

Wasn't it 'a,' not 'A,' that you wanted?

The ratio a/ 30 is the cosine of the angle 22 degrees, which in turn is 0.927:

Then 0.927 = ------- which yields a = 30(0.927) = 27.8 degrees

3 0

2 years ago

You are planning a survey of starting salaries for recent computer science majors. In a recent survey by the National Associatio

nydimaria [60]

Answer:

A sample size of 554 is needed.

Step-by-step explanation:

We have that to find our $\alpha$ level, that is the subtraction of 1 by the confidence interval divided by 2. So:

$\alpha = \frac{1 - 0.95}{2} = 0.025$

Now, we have to find z in the Ztable as such z has a pvalue of $1 - \alpha$ .

That is z with a pvalue of $1 - 0.025 = 0.975$ , so Z = 1.96.

Now, find the margin of error M as such

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

In which $\sigma$ is the standard deviation of the population and n is the size of the sample.

Standard deviation is known to be $12,000

This means that $\sigma = 12000$

What sample size do you need to have a margin of error equal to $1000, with 95% confidence?

This is n for which M = 1000. So

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

$1000 = 1.96\frac{12000}{\sqrt{n}}$

$1000\sqrt{n} = 1.96*12$

Dividing both sides by 1000:

$\sqrt{n} = 1.96*12$

$(\sqrt{n})^2 = (1.96*12)^2$

$n = 553.2$

Rounding up:

A sample size of 554 is needed.

5 0

2 years ago

The number of children at the library was 3 times the number adults. The total number of people at the library was 48. How many

Rufina [12.5K]

Answer:

D 36

Step-by-step explanation:

<em>Write the information algebraically</em>

c = 3a

c + a = 48

c = children, a = adults

<em>In the second sentence (in bold), we can replace c with 3a</em>

c + a = 48 → 3a + a = 48

<em>Simplify</em>

3a + a = 48 → 4a = 48 → a = 12 (divide both sides by 4)

<em>We can then substitute or plug in a = 12 into the original equation:</em>

c + a = 48 → c + 12 = 48 → c = 36 (subtract 12 from both sides)

<h3>There are 36 children</h3>

7 0

2 years ago

Ans this sum plsss .

FrozenT [24]

Answer:

See below ↓

Step-by-step explanation:

2/5
12/25
3/7
3/8
3/10

Draw a number of spacing 0.25 each
Start from -1 to 1
-2/8 = -0.25 [mark on line]
3/6 = 0.5 [mark on line]

Midpoint of -2/5 and 1/2
M = [-2/5 + 1/2] / 2
M = [1/10] / 2
M = 1/20

8 0

2 years ago

How do you find the arc length in a circle given any angle? Give an example.

gogolik [260]

Measure of the central angle that created the arc, the angle of 2 radii, to caculate arc length . The arc length is the fractional amount of the circumference of the circle

3 0

3 years ago