does anyone no how to do this question on math very hard plz explain how to get the answer will mark brailiest 5 star and thx

Given f(x) = x^3 + kx + 9, and x + 1 is a factor of f(x) , then what is the value of the of k?

attashe74 [19]

Can you please help me I really need help with math

8 0

3 years ago

An advisor to the mayor of a large city wants to estimate, within 3 minutes, the mean travel time to work for all employees who

Shkiper50 [21]

Answer:

64

Step-by-step explanation:

Given that an advisor to the mayor of a large city wants to estimate, within 3 minutes, the mean travel time to work for all employees who work within the city limits.

Let X be the random variable denoting the time for employees to travel within city limit

Std dev of X $= 12.25 minutes$

For 95% confidence interval Z critical 1.96 is used because population std dev is known

Margin of error $= 1.96*std error = 3 (given)$

i.e. $1.96(\frac{12.25}{\sqrt{n} } )=3$

where n is the desired sample size.

Simplify to get

$\frac{24.01}{\sqrt{n} } =3\\n=64.053$

Hence atleast 64 employees should he poll

8 0

4 years ago

What is the y-intercept of the quadratic function f(x) = (x – 8)(x + 3)? (8,0) (0,3) (0,–24) (–5,0)

DiKsa [7]

The correct answer is: [C]: " (0, 24) " .
___________________________________________________________

Explanation:
___________________________________________________________

Given the quadratic function:
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→ " y = (x − 8) (x + 3) " ; ← Note: Replace the "f(x)" with: "y" ;

→ Find the "y-intercept".
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→ Note: The "y-intercept" is the coordinate of the point(s) of the graph of the equation at which the graph crosses the "x-axis" when "x = 0" .

→ So; we set plug in "0" for "x" into our equation; and solve for "y" ;

 → " y = (x − 8) (x + 3) " ;

 → y = (0 − 8) (0 + 3) ;

 → y = (-8) * (3) ;

 → y = - 24 ;
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So, the "y -intercept" of the given quadratic function is:

the point at which: "x = 0 ; y = -24 " ;

→ that is; the point the coordinates: " (0, - 24) " ;
___________________________________________________________
→ which is: Answer choice: [C]: " (0, - 24) " .
___________________________________________________________

9 0

3 years ago

Read 2 more answers

What is 0.000000986 in scientific notation? ____x10---

Lilit [14]

$0.000000986 = 986 \times 10^{-9}=\boxed{ 9.86 \times 10^{-7}}$

3 0

4 years ago

Read 2 more answers

A grocery sold 5kg of wheat flour at Rs30 per kg and gained 20%. If he had sold it at Rs27 per kg, what would be his gain or los

maria [59]

Answer:

His gain percent would have been 8%

Step-by-step explanation:

The key to answering this question is to first calculate the price at which the wheat flour was bought.

Mathematically;

% profit = (selling price-cost price)/cost price * 100%

Let the cost price be $x

Thus;

% profit = (30-x)/x * 100

20 = 100(30-x)/x

20x = 3000-100x

100x + 20x = 3000

120x = 3000

x = 3000/120

x = Rs 25

So let’s assume he sold at Rs 27

His profit would have been 27-25 = 2

His gain or loss percentage would’ve been;

2/25 * 100/1 = 200/25 = 8% (gain, since selling price is greater than the cost price)

3 0

3 years ago