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3 years ago

If x=-7 is a root of the equation x^2+kx+49=0, then k=

Mathematics

1 answer:

aleksley [76]3 years ago

8 0

Answer:

$k=14$

Step-by-step explanation:

Given:

$x^{2}+kx+49 = 0$

$x = -7$

Substitution can be used to find the value of $k$ :

$(-7)^{2}+(-7)k+49 = 0$

$49-7k+49 = 0$

$98 -7k = 0$

$k = 14$

Hope this helps :)

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hram777 [196]

Answer:

D: x < 20

Step-by-step explanation:

-4x + 16 > -64

subtract 16 from both sides because you must isolate x.

-4x + 16 - 16 > -64 - 16

-4x > -80

Then divide -4 on both sides... I believe that when you divide a number by a negative number you must flip the sign...

-4x/ -4 < -80/ -4

x < 20

(negative divided by a negative will result in a POSITIVE.)

Hope this helped... I truly apologize if this is wrong..

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3 years ago

A particular restaurant can legally have only 150 people in it at one time. The tables in the restaurant can seat 4 people at a

Alchen [17]

Answer:

a. 37

Step-by-step explanation:

Do 150 divided by 4 so you know how many tables there can be.

150/4

37.5 You can only have 37.5 tables so the awnser is A.37

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3 years ago

HELP!! what inequality is this??

anyanavicka [17]

Answer: y <= 2x+3 or 2x+3 >= y

Step-by-step explanation: Assuming each interval is one unit

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2 years ago

True or false? it's not possible to build a triangle with side lengths of 3 3 and 9

Anit [1.1K]

True

The two shorter lengths do not add up to more than the longest length. 3+3 is less than 9. Therefore, even if the two shorter lengths lay on top of the longer side, the two ends cannot meet to form a closed 3 sided figure

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3 years ago

Read 2 more answers

Suppose 241 subjects are treated with a drug that is used to treat pain and 54 of them developed nausea. Use a 0.05 significance

lana66690 [7]

Answer:

Null Hypothesis, $H_0$ : p = 0.20

Alternate Hypothesis, $H_a$ : p > 0.20

Step-by-step explanation:

We are given that 241 subjects are treated with a drug that is used to treat pain and 54 of them developed nausea.

We have to use a 0.05 significance level to test the claim that more than 20% of users develop nausea.

Let p = population proportion of users who develop nausea

So, Null Hypothesis, $H_0$ : p = 0.20

Alternate Hypothesis, $H_a$ : p > 0.20

Here, null hypothesis states that 20% of users develop nausea.

And alternate hypothesis states that more than 20% of users develop nausea.

The test statistics that would be used here is One-sample z proportion test statistics.

T.S. = $\frac{\hat p-p}{\sqrt{\frac{\hat p(1-\hat p)}{n} } }$ ~ N(0,1)

where, $\hat p$ = proportion of users who develop nausea in a sample of 241 subjects = $\frac{54}{241}$

n = sample of subjects = 241

So, the above hypothesis would be appropriate to conduct the test.

6 0

3 years ago

If x=-7 is a root of the equation x^2+kx+49=0, then k=​

If x=-7 is a root of the equation x^2+kx+49=0, then k=