Answer:
(1, - 2 )
Step-by-step explanation:
Given the 2 equations
3x + y = 1 → (1)
5x + y = 3 → (2)
Subtracting (1) from (2) term by term eliminates the term in y, that is
(5x - 3x) + (y - y) = (3 - 1) and simplifying
2x = 2 ( divide both sides by 2 )
x = 1
Substitute x = 1 in either of the 2 equations for corresponding value of y
Using (1), then
3 + y = 1 ( subtract 3 from both sides )
y = - 2
Solution is (1, - 2 )
Answer:
t-distribution should be used to construct a confidence interval.
Step-by-step explanation:
We are given that a random sample of 18 families, the average weekly food expense was $95.60 with a sample standard deviation of $22.50.
We have to determine whether a normal distribution (Z values) or a t- distribution should be used or whether neither of these can be used to construct a confidence interval.
<em><u>Since in this question we are provided with;</u></em>
Sample average weekly food expense,
= $95.60
Sample standard deviation, s = $22.50
Sample of families, n = 18
The distribution that we will use here to construct a confidence interval will be <u>t-distribution</u> because in the question we don't know anything about population standard deviation
.
Normal distribution is used when we know population standard deviation
.
So, the pivotal quantity for confidence interval that will be used is One-sample t-test statistics;
P.Q. =
~ 
Therefore, t-distribution should be used to construct a confidence interval.
Answer:
Wait what is the question the question you put in was
"PLEASE ANSWER ILL MAKE YOU BRAINLIEST 2 questions"
Step-by-step explanation:
Answer:
-0.9090... can be written as
.
Explanation:
Any <em>repeating </em>decimal can be written as a fraction by dividing the section of the pattern to be repeated <em>by </em>9's.
We can start by listing out
0.909090... = 9/10 + 0/100 + 9/1000 + 0/10000 + 9/100000 + 0/1000000 + ...
Now. we let this series be equal to x, that is
= 9/10 + 0/100 + 9/1000 + 0/10000 + 9/100000 + 0/1000000 + ...
Now, we'll multiply both sides by 100
.
= 90 + 0 + 9/10 + 0/100 + 9/1000 + 0/10000 + ...
Then, subtract the 1st equation from the second like so:
= 90 + 0 + 9/10 + 0/100 + 9/1000 + 0/10000 + 9/100000 + 0/1000000 + ...
= - 9/10 - 0/100 - 9/1000 - 0/10000 - 9/100000 - 0/1000000 - ...
And we end up with this:

Finally, we divide both sides by 99 in order to isolate x and get the fraction we're looking for.

Which can be reduced and simplified to

Hope this helps!
Answer:
use -9 to multiply the first equation
use -4 to multiply the second equation.
Step-by-step explanation:
5x-4y=28.....eqn (1)×-9
3x-9y=30....eqn(2)×-4
-45x+36y=-252
-(-12x+36y=-120)
therefore, -33x÷33 =-132÷-33
x=4.
substitute (x=4) in any of the equation. I'm just going to use eqn 1.
5x-4y=28
5(4)-4y=28
20-4y=28
-4y =28-20
-4y÷-4 = 8÷-4
y=-2
so, x=4, y=-2
Note: for proof of answers substitute the answers for x and y and see if you have the same result...e.g
5(4)-4(-2)=28.