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3 years ago

Find the value of k for x^2 - 2kx+7k -12=0 so that they have two equal roots

Mathematics

1 answer:

Alisiya [41]3 years ago

5 0

Step-by-step explanation:

x^2 -2kx +7k -12 = 0

two equal roots -->Δ = b^2 -4ac = 4k^2 - 4(7k-12)=0 = 4(k^2 - 7k +12)=4(k-4)(k-3)=0

so k =3 and k =4

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Answerrr ASAPPP PLSSS

Genrish500 [490]

Answer: 3^4x5^2

Step-by-step explanation:

4 0

3 years ago

Read 2 more answers

just look at the picture i’m confused, whoever gets it right gets a thanks and brainliest whatever that is lol

DedPeter [7]

Answer:

The three points lie on a straight line

A line through the points passes through the origin

The graph shows a proportional relationship

Step-by-step explanation:

Given statements:

a) The three points do not lie on a straight line.

b) The three points lie on a straight line.

c) A line through the points passes through the origin.

d) A line through the points does not pass through the origin.

e) The graph shows a proportional relationship.

f) The graph does not show a proportional relationship.

For the first and second statements, we can see that the points are able to be connected with a straight, diagonal line (see attached graph). This makes statement a false, and statement b true.

a = false

b = true

For the third and fourth statements, we can see that on the attached (revised) graph on my answer, that the line can continue and pass through the origin, or (0,0). This means that statement c is true, and statement d is false.

c = true

d = false

For the fifth and sixth statements, we know that a relationship is proportional if it is a straight line and passes through the origin when graphed. We have already concluded above that both of these are true, so this means that the graph does represent a proportional relationship. This means that statement e is true, and statement f is false.

e = true

f = false

From the above work, we can conclude that the following statements are true:

b (The three points lie on a straight line)

c (A line through the points passes through the origin)

e (The graph shows a proportional relationship)

Hope this helps :)

5 0

3 years ago

Please give me an approximation of how long it would take to evacuate a population of 91,000 to a destination 21 miles away, usi

RoseWind [281]

Answer:

The time will depend on the number of people who move on each trip from the point of origin to the destination. If done at the maximum speed allowed using 100 vehicles of 50 seats each, the evacuation would be done in 63.68 hours

Step-by-step explanation:

Population = 91,000 ppl

Speed limit = 60 mph

Distance = 21 miles.

1. Assuming that people is evacuated at the max. speed allowed, it means that each trip will take:

T = D/V

D= 21 miles

V = 60 mph:

So;

T = 21 miles / 60mph

T= 0,35 h

2. Asumming that we are going to use an amount of 100 vehicles with 50-seats in each trip for evacuating people, it means that we could evacuate

500 people every 0,35 h ≈ 1,429 ppl/hour (evacuation rate)

To know how long it would take us to evacuate 91,000 people under these conditions, we would have to divide the total amount by the previously calculated evacuation rate

T= 91,000/ 1,429 = 63,68 hours

6 0

3 years ago

How many terms in the sequence are less than 100?

Vaselesa [24]

Answer:

Step-by-step explanation:

Since given, < 100.

So,

100 - 1 = 99

5 0

2 years ago

Two researchers conducted a study in which two groups of students were asked to answer 42 trivia questions from a board game. Th

Verizon [17]

Answer:

$(21.9-19.8) -1.966\sqrt{\frac{3.4^2}{200} +\frac{3.5^2}{200}}= 1.422$

$(21.9-19.8) -1.966 \sqrt{\frac{3.4^2}{200} +\frac{3.5^2}{200}}= 2.778$

And we are 95% confident that the true difference means are between $1.422 \leq \mu_1 -\mu_2 \leq 2.778$

Step-by-step explanation:

We know the following info:

$\bar X_1 = 21.9$ sample mean for group 1

$\bar X_2 = 19.8$ sample mean for group 2

$s_1 = 3.4$ sample standard deviation for group 1

$s_2 = 3.5$ sample standard deviation for group 2

$n_1 = 200$ sample size group 1

$n_2 = 200$ sample size group 2

We want to find a confidence interval for the difference of means and the correct formula to do this is:

$(\bar X_1 -\bar X_2) \pm t_{\alpha/2} \sqrt{\frac{s^2_1}{n_1} +\frac{s^2_2}{n_2}}$

Now we just need to find the critical value. The confidence level is 0.95 then the significance is $1-0.95 =0.05$ and $\alpha/2 =0.025$ . The degrees of freedom are given by:

$df= n_1 +n_2 -2= 200+200-2= 398$

The critical value for this case would be : $t_{\alpha/2}=1.966$

And replacing into the confidence interval formula we got:

$(21.9-19.8) -1.966\sqrt{\frac{3.4^2}{200} +\frac{3.5^2}{200}}= 1.422$

$(21.9-19.8) -1.966 \sqrt{\frac{3.4^2}{200} +\frac{3.5^2}{200}}= 2.778$

And we are 95% confident that the true difference means are between $1.422 \leq \mu_1 -\mu_2 \leq 2.778$

5 0

3 years ago