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2 years ago

Select two answers please!!!!!

Mathematics

1 answer:

Alex2 years ago

6 0

Expanding using the distributive property, we get (x-5)*(x-5)=x^2-5x-5x+25=x^2-10x+25. Multiplying that by -6, we get -6x^2+60x-150 . We then add 12 at the end to get -6x^2+60x-138. Using the quadratic formula (since we want the function to equal 0 to find the zeros), we get x=(-60+-sqrt(3600-3312))/(-6*2)=(-60+-sqrt(288))/-12. For sqrt(288), since 12^2=144 and 144*2=288, we can rewrite it as 12*sqrt(2). Putting that back in, we get
(-60+-(12*sqrt(2))/-12. Factoring it out, we get -5+-sqrt(2)=-5+sqrt(2) or -5-sqrt(2) which is C

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At a company picnic, 1/2 of the people are employees. 2/5 are employees' spouses. What percent are neither?

kupik [55]

Answer:

10% of the people at the picnic are neither.

Step-by-step explanation:

To get the answer,

1/2 + 2/5 = 9/10

10/10 - 9/10 = 1/10

1/10 = 10%

Thanks, I hope I got this right!

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3 years ago

The cross-sectional areas of a triangular prism and a right cylinder are congruent. The triangular prism has a height of 5 units

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2 years ago

If A= [-5,7] and B= [6,10], then find A u B

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Answer:

$\large\boxed{A\ \cup\ B=[-5,\ 10]}$

Step-by-step explanation:

Look at the picture.

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3 years ago

witch rule can you use to find the nth term of an arithmetic sequence in witch the common difference is 5 and a12=63

rewona [7]

Any arithmetic sequence can be expressed as:

a(n)=a+d(n-1), a=initial term, d=common difference, n=term number

We are only told that d=5 and a(12)=63 so:

53=a+5(12-1)

53=a+60-5

53=a+55

a=-2 now we have solved for a and we can say:

a(n)=-2+5(n-1) which neatened up....

a(n)=-2+5n-5

a(n)=5n-7

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3 0

3 years ago

5. The Inland Revenue department claims it takes an average of 6 hours to complete a tax form. Assuming the time to complete the

forsale [732]

Answer:

i) 90.82% of the people can complete the form in more than 5 hours

ii) The probability that the sample mean is less than 6.5 hours is 0.9986 (99.86%)

Step-by-step explanation:

* Lets explain how to sole the problem

- The average time to complete a tax form is 6 hours

- Assuming the time to complete the form is normally distributed with a

standard deviation of 45 minutes

∵ 1 hour = 60 minutes

∴ 45 minutes = 45/60 = 0.75 hour

∴ The standard deviation is 0.75 hour

- We need to know the percentage of the people who complete the

form in more than 5 hours

* Lets use z-score to find the probability

∵ z-score = (x - μ)/σ , where

# x is the score

# μ is the mean

# σ is the standard deviation

∵ μ = 6 , σ = 0.75 , x = 5

∴ $z=\frac{5-6}{0.75}=-1.33$

- Use the normal distribution table to find the corresponding area

of z-score -1.33

∵ The corresponding area of -1.33 = 0.09176

∵ P(x > 5) = 1 - P(z > -1.33)

∴ P(x > 5) = 1 - 0.09176 = 0.90824

- Change it to percentage by multiply it by 100%

∴ P(x > 5) = 0.90824 × 100% = 90.82%

∴ 90.82% of the people can complete the form in more than 5 hours

ii)

- A sample of 20 taxpayers are selected

- We need to know the probability that the sample mean is less

than 6.5 hours

- The sample means is called M

- The standard deviation of the distribution of sample means is

called σM where σM = σ/√n , where σ is the standard deviation and

n is the sample size

- z-score = (M - μ)/σM, where μ is the mean of the population

∵ μ = 6 , σ = 0.75 , n = 20 , M = 6.5 hours

∴ σM = $\frac{0.75}{\sqrt{20}}=0.1677$

∴ $z=\frac{6.5-6}{0.1677}=2.98$

- Use the normal distribution table to find the corresponding area

of z-score 2.98

∵ The corresponding area of 2.98 is 0.99856

∵ P(x < 6.5) = P(z < 2.98)

∴ P(x < 6.5) = 0.99856

∴ The probability that the sample mean is less than 6.5 hours

is 0.9986 (99.86%)

6 0

3 years ago