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
Nata [24]
3 years ago
12

Solve the system by elimination. . 4x-9y=-21 , -4x-3y=9

Mathematics
1 answer:
Ivan3 years ago
7 0
(-3, 1)
4x-9y=-21
+-4x-3y=9
-12y= -12
y=1

4x- 9(1)= -21
4x-9=-21
+9 +9
4x= -12
x=-3
You might be interested in
What mistake did Fumio make? He did not distribute the 2 to both components of vector u. He added vectors v and w before distrib
chubhunter [2.5K]

Answer: A

Step-by-step explanation:

4 0
3 years ago
PLEASE HELP ASAP <br> Which angle is important using the SAS postulate?
Leokris [45]
2,3 I think I’m not sure
7 0
3 years ago
Help me please ..........................
liq [111]
G(x)= (x-4)^2+1......
4 0
3 years ago
Read 2 more answers
he owner of a local supermarket wants to estimate the difference between the average number of gallons of milk sold per day on w
stellarik [79]

Answer:

90% confidence interval is ( -149.114, -62.666   )

Step-by-step explanation:

Given the data in the question;

Sample 1                                Sample 2

x"₁ = 259.23                            x"₂ = 365.12

s₁  = 34.713                              s₂ = 48.297

n₁ = 5                                       n₂ = 10

With 90% confidence interval for μ₁ - μ₂ { using equal variance assumption }

significance level ∝ = 1 - 90% = 1 - 0.90 = 0.1

Since we are to assume that variance are equal and they are know, we will use pooled variance;

Degree of freedom DF = n₁ + n₂ - 2 = 5 + 10 - 2 = 13

Now, pooled estimate of variance will be;

S_p^2 = [ ( n₁ - 1 )s₁² + ( n₂ - 1)s₂² ] / [ ( n₁ - 1 ) + ( n₂ - 1 ) ]

we substitute

S_p^2 = [ ( 5 - 1 )(34.713)² + ( 10 - 1)(48.297)² ] / [ ( 5 - 1 ) + ( 10 - 1 ) ]

S_p^2 = [ ( 4 × 1204.9923) + ( 9 × 2332.6 ) ] / [  4 + 9 ]

S_p^2 = [ 4819.9692 + 20993.4 ] / [  13 ]

S_p^2 = 25813.3692 / 13

S_p^2 = 1985.64378

Now the Standard Error will be;

S_{x1-x2 = √[ ( S_p^2 / n₁ ) + ( S_p^2 / n₂ ) ]

we substitute

S_{x1-x2 = √[ ( 1985.64378 / 5 ) + ( 1985.64378 / 10 ) ]

S_{x1-x2 = √[ 397.128756 + 198.564378 ]

S_{x1-x2 = √595.693134

S_{x1-x2 = 24.4068

Critical Value = t_{\frac{\alpha }{2}, df = t_{0.05, df=13 = 1.771  { t-table }

So,

Margin of Error E =  t_{\frac{\alpha }{2}, df × [ ( S_p^2 / n₁ ) + ( S_p^2 / n₂ ) ]

we substitute

Margin of Error E = 1.771 × 24.4068

Margin of Error E = 43.224

Point Estimate = x₁ - x₂ = 259.23 - 365.12 = -105.89

So, Limits of 90% CI will be; x₁ - x₂ ± E

Lower Limit = x₁ - x₂ - E = -105.89 - 43.224 = -149.114

Upper Limit = x₁ - x₂ - E = -105.89 + 43.224 = -62.666

Therefore, 90% confidence interval is ( -149.114, -62.666   )

3 0
3 years ago
Plz help me i really need this i will give brainliest​
Leno4ka [110]

Step-by-step explanation:

░░░░░▐▀█▀▌░░░░▀█▄░░░

░░░░░▐█▄█▌░░░░░░▀█▄░░

░░░░░░▀▄▀░░░▄▄▄▄▄▀▀░░

░░░░▄▄▄██▀▀▀▀░░░░░░░

░░░█▀▄▄▄█░▀▀░░

░░░▌░▄▄▄▐▌▀▀▀░░ This is Bob

▄░▐░░░▄▄░█░▀▀ ░░

▀█▌░░░▄░▀█▀░▀ ░░ Copy And Paste Him In Brainly Question,

░░░░░░░▄▄▐▌▄▄░░░ So, He Can Take

░░░░░░░▀███▀█░▄░░ Over Brainly

8 0
3 years ago
Read 2 more answers
Other questions:
  • Question on a picture<br>​
    7·1 answer
  • Math when is the sum of two negative mixed numbers an integer
    15·1 answer
  • Help please !!!!!!!!!!!!!
    8·1 answer
  • g A random variable X has a probability density function fX(x) = ? 0.5 sin(x) , 0 ≤ x ≤ π 0 , otherwise Another random variable
    7·1 answer
  • What is the word form of the number 43.06?
    10·2 answers
  • Which equation does not represent a function?
    13·1 answer
  • MZFEG=6x - 7 and mZFED=2x +41 , find the mZDEG
    15·1 answer
  • 18 000 mg = ____ kg?<br>It's ez, just me the problem :)​
    14·2 answers
  • Round 7, 488 to the nearest thousands​
    14·2 answers
  • Need help these 3 math ?​
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!