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3 years ago

Samantha conjectures that for x < -1, it is true that x5 - 2 > x. Is her conjecture correct? Why or why not?

Mathematics

1 answer:

Ronch [10]3 years ago

4 0

Answer:

The conjecture cannot work for any negative numbers, It works for x > 1.3.

Step-by-step explanation:

An odd power preserves the sign. For |x| > 1, the power increases the magnitude. For x < 0, adding -2 only increases the magnitude more. A negative number of larger magnitude will not be "greater than" the reference. It will be "less than."

It only takes a counterexample to show the conjecture is incorrect.

x^5 -2 ?? x

(-2)^5 -2 ?? (-2)

-32 -2 ?? -2

-34 < -2 . . . . . . not greater than

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172.7=3.14d <br> Solve for d

Serga [27]

Answer:

Step-by-step explanation:

Divide both sides by 3.14 to get d by itself.

172.7 / 3.14 = 55 = d

4 0

3 years ago

A chemist examines 12 sedimentary samples for bromide concentraction. The mean bromide concentration for the sample date is 0.43

Umnica [9.8K]

Answer:

a) $z = 1.645$

b) Lower endpoint: 0.422cc/m³

Upper endpoint: 0.452 cc/m³

Step-by-step explanation:

Population is approximately normal, so we can find the normal confidence interval.

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

$\alpha = \frac{1-0.9}{2} = 0.05$

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

So it is z with a pvalue of $1-0.05 = 0.95$ , so $z = 1.645$ . This is the critical value, the answer for a).

Now, find 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.

$M = 1.645*\frac{0.0325}{\sqrt{12}} = 0.015$

The lower end of the interval is the sample mean subtracted by M. So it is 0.437 - 0.015 = 0.422cc/m³.

The upper end of the interval is the sample mean added to M. So it is 0.437 + 0.015 = 0.452 cc/m³.

Lower endpoint: 0.422cc/m³

Upper endpoint: 0.452 cc/m³

4 0

3 years ago

Please help on this question?

svlad2 [7]

Well we know these two angles are congruent, so we set their angles equal to each other.
5w - 69 = w + 3
4w = 72
w = 18
Now we plug w back into one of the equations, and then multiply whatever number we get by 2.
18 + 3 = 21
21 x 2 = 42
The measure of STU is 42°

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2 years ago

Solve for z -p(d+z) = -2z+59

Aleksandr-060686 [28]

Here you go. Let me know if you have questions

3 0

3 years ago

20 POINTS AND BRAINLIEST !! PLEASE ANSWER THIS QUESTION !!

Elenna [48]

A
(X-7)(x-4) -> x^2 -11x + 28
Multiply that by the 2 and you get the original equation!

5 0

3 years ago