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2 years ago

Consider the expressions 3x(x − 2) + 2 and 2x2 + 3x − 18.

Mathematics

1 answer:

Rzqust [24]2 years ago

4 0

Answer:

See answer below

Step-by-step explanation:

For the first expression

3 x (x - 2) + 2 = 3 x^2 - 6 x + 2

evaluated at x= 4 we get: 26

and for x = 5 we get 47.

For the second expression

2 x^2 + 3 x - 18

we get the exact same values when doing the evaluation at these two points.

Based on those results, one may think the expressions may be equivalent, but they are not equivalent. Because at any other x-value, their results are different. See for example that for x = 0 the first one gives "2" while the second one gives -18.

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You have $.80 in your backpackin dimes and quarters. Let x represent the number of dimes and y

Nonamiya [84]

Answer:

$0.10x + $0.25y = $0.80

8 0

2 years ago

20% of US High School teens vape. A local High School has implemented campaigns to reduce vaping among students and believes tha

zaharov [31]

Answer:

10.93% probability of observing 51 or fewer vapers in a random sample of 300

Step-by-step explanation:

I am going to use the normal approximation to the binomial to solve this question.

Binomial probability distribution

Probability of exactly x sucesses on n repeated trials, with p probability.

Can be approximated to a normal distribution, using the expected value and the standard deviation.

The expected value of the binomial distribution is:

$E(X) = np$

The standard deviation of the binomial distribution is:

$\sqrt{V(X)} = \sqrt{np(1-p)}$

Normal probability distribution

Problems of normally distributed samples can be 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.

When we are approximating a binomial distribution to a normal one, we have that $\mu = E(X)$ , $\sigma = \sqrt{V(X)}$ .

In this problem, we have that:

$n = 300, p = 0.2$

$\mu = E(X) = np = 300*0.2 = 60$

$\sigma = \sqrt{V(X)} = \sqrt{np(1-p)} = \sqrt{300*0.2*0.8} = 6.9282$

What is the approximate probability of observing 51 or fewer vapers in a random sample of 300?

Using continuity corrections, this is $P(X \leq 51 + 0.5) = P(X \leq 51.5)$ , which is the pvalue of Z when X = 51.5 So

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

$Z = \frac{51.5 - 60}{6.9282}$

$Z = -1.23$

$Z = -1.23$ has a pvalue of 0.1093.

10.93% probability of observing 51 or fewer vapers in a random sample of 300

4 0

3 years ago

Im learning Polynomials and we are learning the strategy grouping, can anyone please explain how to group polynomials and maybe

crimeas [40]

Grouping is when you have to terms that are the same inside the parenthesis and a different or same number outside the parenthesis and then the one inside the parenthesis u are going to group them not combined them and write them once and the numbers inside the parenthesis group them together by adding them and put parenthesis between them

Ex
5(4x+1)10(4x+1)
(5+10)(4x+1)

6 0

3 years ago

Read 2 more answers

Polly’s favorite cereal has 270 calories. The nutrition label on the box states that 56 of the calories come from fat. How many

Crazy boy [7]

I'm going to assume that you mean 56% of the calories come from fat. So, we would have to find out 56% of 270 which is 151.2, so now we know that 151.2 calories in the cereal come from fat!

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3 years ago

Write a slope intercept equation for line with the given characteristics m=-3/5 passes through (4,-4)

Ber [7]

Step-by-step explanation:

Hey there!

Given;

Slope (m) = -3/5

And passes through the point(4,-4).

Now; The equation of a line in slope intercept form is y= mx+b.

So, try to bring it in y= mx+b form.

Firstly let's use one-point formula.