1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Harman [31]
4 years ago
8

Write a quadratic equation whose solutions are 7i and -7i

Mathematics
1 answer:
mrs_skeptik [129]4 years ago
4 0
x = \pm 7i  \\  \\ x^2 = -49 \\  \\ x^2 +49 = 0
You might be interested in
A team averaging 110 points is likely to do very well during the regular season. The coach of your team has hypothesized that yo
aev [14]

Answer:

1. M=108

2. μ=110

3. In the explanation.

4. Test statistic t = -1.05

5. P-value = 0.1597

Step-by-step explanation:

The question is incomplete: to solve this problem, we need the sample information: size, mean and standard deviation.

We will assume a sample size of 10 matches, a sample mean of 108 points and a sample standard deviation of 6 points.

1. The mean points is the sample points and has a value of 108 points.

2. The null hypothesis is H0: μ=110, meaning that the mean score is not significantly less from 110 points.

3. This is a hypothesis test for the population mean.

The claim is that the mean score is significantly less than 110.

Then, the null and alternative hypothesis are:

H_0: \mu=110\\\\H_a:\mu< 110

The significance level is 0.05.

The sample has a size n=10.

The sample mean is M=108.

As the standard deviation of the population is not known, we estimate it with the sample standard deviation, that has a value of s=6.

The estimated standard error of the mean is computed using the formula:

s_M=\dfrac{s}{\sqrt{n}}=\dfrac{6}{\sqrt{10}}=1.9

4. Then, we can calculate the t-statistic as:

t=\dfrac{M-\mu}{s/\sqrt{n}}=\dfrac{108-110}{1.9}=\dfrac{-2}{1.9}=-1.05

The degrees of freedom for this sample size are:

df=n-1=10-1=9

5. This test is a left-tailed test, with 9 degrees of freedom and t=-1.05, so the P-value for this test is calculated as (using a t-table):

\text{P-value}=P(t

As the P-value (0.1597) is bigger than the significance level (0.05), the effect is  not significant.

The null hypothesis failed to be rejected.

There is not enough evidence to support the claim that the mean score is significantly less than 110.

7 0
3 years ago
The original price of a new book is $140.00. If the book is marked down
11Alexandr11 [23.1K]

Answer:

112.00

Step-by-step explanation:

140.00=100%

? =80%

80×140÷100=112.00

=$112.00

8 0
3 years ago
rachel rides her bicycle due east at 9 miles per hour.Amos rides his bicycle due north at 12 miles per hour. if they left from t
Phantasy [73]

Answer:

15 miles

Step-by-step explanation:

pythagorean theorem

9²+12²=x²

x=15 miles

5 0
3 years ago
Thomas works as a salesperson on Saturday and Sunday at the verizon store he is payed 46.50 each day and for every smart phone h
Triss [41]
So he is paid 46.5 flat  every day
he earns 5% of each smart phone he sells
at the time of the problem, smart phones sell for 70 so he earns 5% or 70 or 5/100 of 70 or 1/20 of 70 or 70/20 or 7/2 or 3 and 1/2 or $3.50 per phone he sells

so pay must be at lease 150 so
pay=46.5+ (# of phones times 3.50)
150<u><</u>46.50+(number of pones times 3.50)
solve for number of phones
subtract 46.5 from both sides
103.5<u><</u>(number of phonest imes 3.5)
divdie both sides by 3.5
29.57<u><</u>number of phones
round up since can't sell a fraction of a phone
30
he has to sell at leas 30 phones
4 0
3 years ago
the perimeter of a pool table is 30 ft.The table is twice as long as it is wide.what is the length of the pool table.
noname [10]
Perimeter is legnth +legnth + width + width or
P=2L+2W

L=2W
subsitute L=2W for L in P=2L+2W

P=2(2W)+2W
P=4W+2W
P=6W

we know that Perimiter=30 so
30=6W
divide both sides by 6
5=Width

subsitute W=5 for W in L=2W
L=2(5)
L=10

to check
10=2(10)+2(5)
30=20+10
30=30
checks


Legnght=10
Width=5
4 0
4 years ago
Other questions:
  • Which symbol creates a true sentence when x equals 6? 42 + (x – 3)2 __ 28
    12·2 answers
  • 30 points if you can answer this question and tell me how to do it
    15·1 answer
  • 1. If your mom made you a delicious kale and quinoa salad that require 20ml of pickle juice and she wants to make two more salad
    7·1 answer
  • - Match each sentence with the appropriate equation.
    11·1 answer
  • 2/5(5k+35) -8 =12 please helpppppppp
    8·2 answers
  • What is the solution for the equation?
    13·1 answer
  • In the triangle shown, B=60 and AC=9√3 how long is AB answer exactly, use a radical if needed
    12·1 answer
  • Yuron is sketching a scale drawing of a famous painting. The painting is 54 inches wide and 72 inches long. He used a scale fact
    10·1 answer
  • 1. last question. please help me out thank you. ill mark you brainlist
    15·2 answers
  • I got homework and I need help with it and starr testing is soon so I need big help
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!