All categories

2 years ago

Is 9999 in the sequence n²+2n?

Mathematics

1 answer:

Tamiku [17]2 years ago

8 0

Answer:

Step-by-step explanation:

To find out, all we need to do is plug in 9999 into the sequence.

$9999 = n^2 + 2n$

By completing the square, we get $(n+1)^2 = 1001$ . 1001 is not a perfect square, which means that 9999 is not in the sequence.

hope this helped! :)

You might be interested in

Notebook cost $8.50 plus sales tax. After sales tax, The Notebook is $8.86. What is the sale tax rate?

statuscvo [17]

Answer:what is 86-50=36 us the tax rate

Step-by-step explanation:

5 0

3 years ago

Solve the system of equations.

Xelga [282]

Answer:

b. x=1, y=2, z=3

Step-by-step explanation:

The system of equations ...

3x +2y +z = 10
9x -6y +z = 0
x -y -3z = -10

has solution (x, y, z) = (1, 2, 3) . . . . matches choice B.

_____

While it is convenient to solve this using a graphing calculator or web site, one can easily solve the system by hand.

Subtract the second equation from 3 times the first:

3(3x +2y +z) -(9x -6y +z) = 3(10) -(0)

12y + 2z = 30 . . . . simplify

Dividing this result by 2 gives ...

6y +z = 15 . . . . . . [eq4]

Subtract 3 times the third equation from the first:

(3x +2y +z) -3(x -y -3z) = (10) -3(-10)

5y +10z = 40 . . . . simplify

y + 2z = 8 . . . . . . . divide by 5 . . . . . [eq5]

The two equations [eq4] and [eq5] can be solved any of the ways you usually solve two equations in two variables. Here, we'll use the first equation to write an expression for z that we can substitute into the second equation.

z = 15 -6y . . . . . subtract 6y from [eq4]

y + 2(15 -6y) = 8 . . . . . substitute for z in [eq5]

-11y +30 = 8 . . . . . simplify

-11y = -22 . . . . . . . subtract 30

y = 2 . . . . . . . . . . . divide by the coefficient of y

z = 15 -6(2) = 3 . . . . substitute for y in our equation for z

Substituting these values for y and z into the third original equation gives ...

x - 2 -3(3) = -10

x -11 = -10 . . . . . . . . simplify

x = 1 . . . . . . . . . . . . add 11

The solution to the above system of equations is (x, y, z) = (1, 2, 3).

_____

<em>Comment on the problem statement</em>

Math is generally unforgiving of imprecision. The given system of equations has no variable "z", and some other typos are apparently involved. That is why we rewrote the system to the equations shown above.

It is very easy to mistake z for 2, or g for 9, or o for 0, or 1 for 7. There are other confusions that are possible, as well. Letters I (eye) and l (ell) are easily confused, and may be confused with 1 (one) as well. Sometimes y and 4, or 4 and 9, can also be written so as to be difficult to tell apart. Great care must be taken when handwriting these symbols.

7 0

4 years ago

An automobile manufacturer claims that its jeep has a 53.9 miles/gallon (MPG) rating. An independent testing firm has been contr

Advocard [28]

Answer:

Value of the test statistic, $z_{test} = - 1.17$

Step-by-step explanation:

Null hypothesis, $H_{0}: \mu = 53.9$

Alternative hypothesis, $H_{a} : \mu \neq 53.9$

Sample mean, $\bar{X} = 53.7$

Sample size, n = 110

Standard deviation, $\sigma = 1.8$

Significance level, $\alpha = 0.02$

The value of the test statistics is given by the formula:

$z_{test} = \frac{\bar{X} - \mu}{\frac{\sigma}{\sqrt{n} } } \\z_{test} = \frac{53.7 - 53.9}{\frac{1.8}{\sqrt{110} } } \\z_{test} = - 1.17$

7 0

3 years ago

Percentage grade averages were taken across all disciplines at a particular university, and the mean average was found to be 83.

Paha777 [63]

Correct Answer:
Option A. 0.01

Solution:
This is a problem of statistics and uses the concept of normal distributions. We need to convert the score of 90 into z-score and then find the desired probability from standard normal distribution table.

Converting 90 to z-score:

$z= \frac{90-83.6}{ \frac{8.7}{ \sqrt{10}} }=2.33$

Now we are to find the probability of z score being more than 2.33. From the z-table the probability comes out to be 0.01.

Therefore, we can conclude that the probability of class average is greater than 90 is 0.01.

4 0

3 years ago

The equation of line a is y=12x−1, and it passes through point (6,2).

Triss [41]

Answer:

A). slope = -1/12 y-intercept = 3/2

Step-by-step explanation:

y = -1/12x + b

2 = -1/12(-6) + b

2 = 1/2 + b

3/2 = b

y = -1/12x + 3/2

3 0

3 years ago

Is 9999 in the sequence n²+2n?​

Is 9999 in the sequence n²+2n?