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3 years ago

Use the Quadratic formula to solve: x^2 + 10 =-7x

2 answers:

8 0

$x^2 + 10 =-7x\\x^2 +7x+ 10 =0 \\\\ x= \cfrac{-7б \sqrt{7^2-4*1*10} }{2}=x= \cfrac{-7б \sqrt{49-0} }{2}= \cfrac{-7б 3 }{2} \\ \\ x=\cfrac{-7- 3 }{2}=-5\\\\ x=\cfrac{-7+ 3 }{2}=-2$

Answer: x=-5, x=-2

seropon [69]3 years ago

8 0

The answer are -5 and -2

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3 years ago

F'(-7, 13) was dilated by a scale factor of 2 about (-2, -5), the resulting image is___

AveGali [126]

The resulting image of the point F(x, y) = (- 7, 13) is F'(x, y) = (- 12, 31).

<h3>What is the resulting image of a point by rigid transformation?</h3>

In this problem we have a point that has to be transformed by a kind of rigid transform known as dilation, which is defined by the following equation:

P'(x, y) = O(x, y) + k · [P(x, y) - O(x, y)] (1)

Where:

O(x, y) - Center of dilation
P(x, y) - Original point
P'(x, y) - Image
k - Scale factor

If we know that O(x, y) = (- 2, - 5), F(x, y) = (- 7, 13) and k = 2, then the resulting image is:

F'(x, y) = (- 2, - 5) + 2 · [(- 7, 13) - (- 2, - 5)]

F'(x, y) = (- 2, - 5) + 2 · (- 5, 18)

F'(x, y) = (- 2, - 5) + (- 10, 36)

F'(x, y) = (- 12, 31)

The resulting image of the point F(x, y) = (- 7, 13) is F'(x, y) = (- 12, 31).

To learn more on rigid transformations: brainly.com/question/28004150

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2 years ago

I need help with number 29.

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Answer:

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Step-by-step explanation:

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3 years ago

The plate is rotated 90° about the origin in the counterclockwise direction. In the image trapezoid, what are the coordinates of

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4 years ago

Read 2 more answers

Ronald scores 700 on the math section of the SAT exam. The distribution of SAT scores is approximately normal with a mean of 500

Artist 52 [7]

Answer:

a) Due to the higher z-score, Ronald performed better relative to his peers on the test.

b) Ronald needed a grade of at least 732.5, and Rubin of at least 33.58.

c) 95% of the population fall between graded of 4.868 and 31.132 on the ACT.

95% of the population fall between graded of 304 and 696 on the SAT.

Step-by-step explanation:

Normal probability distribution

When the distribution is normal, we use the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

In this question:

(a) Relative to their peers who also took the tests, who performed better on his test? Explain.

We have to find whoever has the higher z-score.

Ronald:

Ronald scores 700 on the math section of the SAT exam. The distribution of SAT scores is approximately normal with a mean of 500 and a standard deviation of 100. So the z-score is found when $X = 700, \mu = 500, \sigma = 100$ . So

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{700 - 500}{100}$

$Z = 2$

Rubin:

Rubin takes the ACT math exam and scores 31 on the math portion. ACT scores are approximately normally distributed with a mean of 18 and a standard deviation of 6.7. So the z-score is found when $X = 31, \mu = 18, \sigma = 6.7$ . So

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{31 - 18}{6.7}$

$Z = 1.94$

Due to the higher z-score, Ronald performed better relative to his peers on the test.

(b) A certain school will only consider those students who score in the top 1% in the math section. What grades would Ronald and Rubin have to receive on their respective tests to be considered for admission?

They have to be in the 100 - 1 = 99th percentile, that is, they need a z-score with a pvalue of at least 0.99. So we need to find for them X when Z = 2.325.

Ronald:

$Z = \frac{X - \mu}{\sigma}$

$2.325 = \frac{X - 500}{100}$

$X - 500 = 232.5$

$X = 732.5$

Rubin:

$Z = \frac{X - \mu}{\sigma}$

$2.325 = \frac{X - 18}{6.7}$

$X - 18 = 15.58$

$X = 33.58$

Ronald needed a grade of at least 732.5, and Rubin of at least 33.58.

(c) Between what two grades does 95% of the population fall for the ACT and the SAT exams?

They fall between the 100 - (95/2) = 2.5th percentile and the 100 + (95/2) = 97.5th percentile, that is, they fall between X when Z = -1.96 and X when Z = 1.96.

ACT:

Lower bound:

$Z = \frac{X - \mu}{\sigma}$

$-1.96 = \frac{X - 18}{6.7}$