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
allochka39001 [22]
3 years ago
7

X^2 +8 =0 please show all work

Mathematics
1 answer:
Virty [35]3 years ago
6 0
x^2+8=0\\
x^2=-8\\
x=-\sqrt{-8} \vee x=\sqrt{-8}\\
x=-\sqrt{8\cdot(-1)} \vee x=\sqrt{8\cdot(-1)}\\
x=-\sqrt{8}\cdot\sqrt{-1} \vee x=\sqrt{8}\cdot\sqrt{-1}\\
x=-\sqrt{4}\cdot \sqrt2\cdot i \vee x=\sqrt{4}\cdot \sqrt 2\cdot i\\
x=-2\sqrt{2}i \vee x=2\sqrt{2}i

You might be interested in
Please help me answer this with the correct answer :)
Andru [333]

Answer:

A.

Step-by-step explanation:

Amber get $150 per week no matter wut and +$10 per tree sold so if she sells 5 trees she gets a total of $200

Jorge gets $25 per tree sold and an extra $75at the end of the week so 25(5)=125+75=200 so they both end up with $200 at the end of the week

4 0
3 years ago
A sample of 12 radon detectors of a certain type was selected, and each was exposed to 100 pCI/L of radon. The resulting reading
valkas [14]

Answer:

Null hypothesis:\mu = 100  

Alternative hypothesis:\mu \neq 100  

t=\frac{98.375-100}{\frac{6.109}{\sqrt{12}}}=-0.921  

p_v =2*P(t_{11}  

Step-by-step explanation:

1) Data given and notation  

Data: 105.6, 90.9, 91.2, 96.9, 96.5, 91.3, 100.1, 105.0, 99.6, 107.7, 103.3, 92.4

We can calculate the sample mean and deviation for this data with the following formulas:

\bar X =\frac{\sum_{i=1}^n X_i}{n}

s=\sqrt{\frac{\sum_{i=1}^n (X_i- \bar X)^2}{n-1}}

The results obtained are:

\bar X=98.375 represent the sample mean  

s=0.6.109 represent the sample standard deviation  

n=12 sample size  

\mu_o =100 represent the value that we want to test  

\alpha represent the significance level for the hypothesis test.  

z would represent the statistic (variable of interest)  

p_v represent the p value for the test (variable of interest)  

2) State the null and alternative hypotheses.  

We need to conduct a hypothesis in order to check if the mean is equal to 100pCL/L, the system of hypothesis are :  

Null hypothesis:\mu = 100  

Alternative hypothesis:\mu \neq 100  

Since we don't know the population deviation, is better apply a t test to compare the actual mean to the reference value, and the statistic is given by:  

t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}} (1)  

t-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".  

3) Calculate the statistic  

We can replace in formula (1) the info given like this:  

t=\frac{98.375-100}{\frac{6.109}{\sqrt{12}}}=-0.921  

4) P-value  

First we need to find the degrees of freedom for the statistic given by:

df=n-1=12-1=11

Since is a two sided test the p value would given by:  

p_v =2*P(t_{11}  

5) Conclusion  

If we compare the p value and the significance level assumed \alpha=0.05 we see that p_v>\alpha so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, so we can conclude that the true mean is not significant different from 100 at 5% of significance.  

3 0
3 years ago
Factor each expression by factoring out the common binomial <br><br> 5a(y + 4) + 8(y + 4)
Tems11 [23]

Answer:

Factoring the term 5a(y + 4) + 8(y + 4) we get (y+4)(5a+8)

Step-by-step explanation:

We need to factor the term: 5a(y + 4) + 8(y + 4)

Factoring:

5a(y + 4) + 8(y + 4)

Taking (y+4) common

(y+4)(5a+8)

It cannot be further factored.

So, Factoring the term 5a(y + 4) + 8(y + 4) we get (y+4)(5a+8)

6 0
3 years ago
. Curt is installing a picket fence around his garden which is 45.45 ft by 14.63 ft. When he gets to the hardware store he finds
Dmitriy789 [7]
The fence must have two sides of length 45.45 ft and two sides of length 14.63

To cover each of 45.45 ft long side, he will need 45.45 /  2 = 22.7 slats which approximates to 23. So, they are 2 * 23 = 46 slats.

To cover each of 14.63 ft sides, he will need 14.63 / 2 = 7.3 which approximates to 8 (to not leave any spaces between each slat). So, they are 2 * 8 = 16 slats.

That makes 46 + 16 = 62 slats.

Answer: around 62 slats.
5 0
3 years ago
Absolute value inequalities with fractions
Harlamova29_29 [7]
|x - 2x/5| <= 10
|5x - 2x| <= 50
3x <= 50
  x <= 50/3

-|5x - 2x| <= 50
-3x <= 50
   x >= - 50/3

answer

-50/3 <=  x <= 50/3


3 0
3 years ago
Other questions:
  • Can anyone help!? Points are high!
    13·2 answers
  • Gavin's anemometer measures the wind speed at 44.14 kilometers per hour. 4 times faster than the wind speed 5 hours ago.
    6·2 answers
  • Simplify 2 (n+1) + n² + 4 (n-3)
    12·2 answers
  • Round 344,501 to the nearest 10,000
    9·1 answer
  • Solve the formula for n. A=a+d(n-1) evaluate n when A=25, a=5, and d=13
    14·1 answer
  • Hi :) this lesson is about 30-60-90 triangles.
    7·1 answer
  • Which of these lists bodies in order, from CLOSEST to FURTHEST from the Earth
    14·2 answers
  • Find the relative minimum of<br> y = 3x^3 + 14x^2 - 11x - 46<br><br>(___, ___)​
    11·1 answer
  • The equation y = 1.09x describes the approximate number of yards y in x meters. About how many meters is a 40 yard race?
    15·1 answer
  • What is the answer to this one need asap
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!