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3 years ago

Solve the system of equations using elimination.

Mathematics

1 answer:

olasank [31]3 years ago

5 0

Answer:

The solution would be D) (5, -8)

Step-by-step explanation:

To use this method, start by multiplying the second equation by -1. Then add the two equations together.

8x + 7y = -16

-10x - 7y = 6

------------------

-2x = -10

x = 5

Now that we have the value of x, use it to solve either equation for y.

10x + 7y = -6

10(5) + 7y = -6

50 + 7y = -6

7y = -56

y = -8

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2 years ago

A set of exam scores is normally distributed and has a mean of 80.2 and a standard deviation of 11. What is the probability that

ZanzabumX [31]

Answer:

93.32% probability that a randomly selected score will be greater than 63.7.

Step-by-step explanation:

Problems of normally distributed samples are solved using 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 problem, we have that:

$\mu = 80.2, \sigma = 11$

What is the probability that a randomly selected score will be greater than 63.7.

This is 1 subtracted by the pvalue of Z when X = 63.7. So

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

$Z = \frac{63.7 - 80.2}{11}$

$Z = -1.5$

$Z = -1.5$ has a pvalue of 0.0668

1 - 0.0668 = 0.9332

93.32% probability that a randomly selected score will be greater than 63.7.

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4 years ago

Let fx) = 8x - 3<br> What is f(5)?

mihalych1998 [28]

f(5) means to replace the x in the equation with 5.

f(5) = 8(5) - 3

f(5) = 40 - 3

f(5) = 37

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3 years ago

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sattari [20]

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3 years ago

A pitcher holds 3 liters of lemonade. If the contents of the pitcher are equally divided among 8 people, how much lemonade will

igomit [66]

Answer:

0.375 litres

Step-by-step explanation:

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Total amount of lemonade held by pitcher = 3 litres

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3 years ago