Which one is correct?

Mr. Walker gave his class the function f(x) = (x + 3)(x + 5). Four students made a claim about the function. Each student’s clai

Scrat [10]

the only student that is correct is Stepheh. "The vertex is at (–4, –1)."

<h3>Which claims are true?</h3>

Here we have the quadratic equation:

f(x) = (x + 3)*(x + 5)

The first claim is: "The y-intercept is at (15, 0)."

This is clearly false, as the y-intercept is at x = 0, and in that point we have x = 15.

The second claim is:

"The x-intercepts are at (–3, 0) and (5, 0)"

This is false, in the factored equation we can see that the x-intercepts are x =-3 and x = -5.

Third claim:

"The vertex is at (-4, -1)"

The middle value between the zeros is:

(-3 + (-5))/2 = -4

Evaluating the function in x = -4 we get the y-value of the vertex:

f(-4) = (-4 + 3)*(-4 + 5) = -1*1 = -1

So the vertex is at (-4, -1), this claim is true.

The fourth claim is:

"The midpoint between the x-intercepts is at (4, 0)."

Which is false, we already saw that the midpoint between the x-intercepts is at x = -4

Then the only student that is correct is Stepheh. "The vertex is at (–4, –1)."

If you want to learn more about quadratic equations:

brainly.com/question/1214333

#SPJ1

3 0

2 years ago

If f(x) = -7x + 5x2 + 10, what does f(-2) equal?

Mkey [24]

F(x) = -7x + 5x² + 10

x = -2

substitute the x by its value

f(-2) = -7(-2) + 5(-2)² + 10
f(-2) = 14 + 5(4) + 10
f(-2) = 14 + 20 + 10
f(-2) = 44

8 0

3 years ago

A store sells black ink pens for $5 and red ink pens for $4. John wishes to buy 20 pens but doesn’t wish to spend more than $92.

Zina [86]

Answer: $4r + 5(20-r) \le 92$

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Explanation:

r = number of red pens

4r = cost of buying r red pens

example: if r = 10, then 4r = 4*10 = 40 is the total cost of buying 10 red pens

If John buys r red pens, then he must buy 20-r black pens so that r and 20-r add to 20.

John buys 20-r black pens, and at $5 each, so it will cost 5(20-r) dollars for just the black pens alone.

In total, John spends 4r + 5(20-r) dollars for all the pens (red & black)

We want $92 be the most he spends. This is the ceiling or highest value possible.

Therefore,

$4r + 5(20-r) \le 92$

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Extra info:

If you want to solve for r, then

$4r + 5(20-r) \le 92$

$4r + 5(20)+5(-r) \le 92$ distribute

$4r + 100 - 5r \le 92$

$100 - r \le 92$

$100-r+r \le 92+r$ add r to both sides

$100 \le 92+r$

$100-92 \le 92+r-92$ subtract 92 from both sides

$8 \le r$

$r \ge 8$

So John must buy at least 8 red pens. The most he can buy is 20 red pens since he wants 20 pens total.

8 0

3 years ago

Can y’all help me with dis question

kykrilka [37]

Pretty sure is A or D.

6 0

3 years ago

It is a well known fact that talking on a cell phone impairs a driver more than talking to a person sitting in the passenger sea

sergey [27]

Answer:

The statistical test to use in comparing the number or words spoken for people with and without licenses is independent sample t test.

Step-by-step explanation:

The sample test to use is an Independent Samples t Test. The reason for using this statistical test is because it takes two independent groups; calculates and compares the means of these groups so as to determine if statistical evidence exists such that the associated population means are significantly different.

In this case, there are two groups of passengers (40, in total);

Group 1 are those who have driving licence while group 2 are those who do not.

Depending on the response from these two groups, the independent sample t test calculates the mean and compares the number or words spoken for people with and without licenses to know passengers experience.

3 0

3 years ago