What is the first step to solve the following system of equations using substitution?
X-y=-1
2x-y=3
A.) Solve the first equation for x.
B.) Divide the second equation by 2.
C.) Multiply the first equation by 2.
D.) Add the two equations together.
Answer:
Step 1: Solve one of the equations for one of the variables. Let's solve the first equation for x
Thus, option A) is true.
The solution to the system of equations be:
[tex]x = 4, y = 5[/tex]
Step-by-step explanation:
It is important to remember that when we solve the system of equations, the first step we need to do is to solve one of the equations for one of the variables.
Given the system of equations
[tex]x - y = -1[/tex]
[tex]2x - y = 3[/tex]
Step 1: Solve one of the equations for one of the variables. Let's solve the first equation for x
[tex]x-y=-1[/tex]
Add y to both sides
[tex]x-y+y=-1+y[/tex]
[tex]x=-1+y[/tex]
Thus, option A) is true.
NOW LET US SOLVE THE REMAINING PORTION
[tex]\mathrm{Subsititute\:}x=-1+y[/tex] to solve for y
[tex]\begin{bmatrix}2\left(-1+y\right)-y=3\end{bmatrix}[/tex]
[tex]-2+y=3[/tex]
[tex]y=5[/tex]
For x = -1 + y
substitute y = 5
[tex]x=-1+5[/tex]
[tex]x=4[/tex]
Thus, the solution to the system of equations be:
[tex]x = 4, y = 5[/tex]
The manager of a grocery store has selected a random sample of 100 customers. The average length of time it took these 100 customers to check out was 3.0 minutes. It is known that the standard deviation of the checkout time is 1 minute. Refer to Exhibit 8-2. If the confidence coefficient is reduced to .80, the standard error of the mean _____.
Answer:
The standard error of the mean remains unchanged.
Step-by-step explanation:
Given that:
The standard error (S.E) of the mean [tex]= \dfrac{\sigma}{\sqrt{n}}[/tex] with is independent of confidence coefficient.
The margin of error [tex]E = z \times S.E[/tex]
This explains the claim that as the confidence coefficient reduces, the z-value also reduces, so as the Margin of error (E) but the standard error will always remain unchanged.
i.e.
From the question;
sample size n = 100
standard deviation = 1
mean = 3.0
The standard error (S.E) of the mean [tex]= \dfrac{1}{\sqrt{100}}[/tex]
= 0.1
So, if the confidence coefficient is reduced to 0.80, the standard error of the mean remains unchanged.
At the farmer's market,
eight peaches (x) plus
three cantaloupe (y) cost
$63. Two peaches plus
three cantaloupe cost $27.
How much does each fruit
costo
Answer:
Cantaloupe = $6, peach=$5
Step-by-step explanation:
[tex]8x+3y=63\\2x+3y=27\\[/tex]
Subtract the first one from the second one
[tex]8x-2x+3y-3y=63-27\\6x=36\\x=6\\[/tex]
Plug in:
[tex]2(6)+3y=27\\12+3y=27\\3y=15\\y=5[/tex]
Hope this helps plz hit the crown :D
(Identify the type of sampling method used.) A candidate for the senate creates an automated message that calls every third listed phone number and reminds them to vote for him in the upcoming election.
Convenience Sampling
Cluster Sampling
Systematic Sampling
Stratified Sampling
Answer:
Systematic Sampling
Step-by-step explanation:
Systematic sampling is one of the types of probability sampling method. It is an advanced form of simple random sampling. In this form, from the population of members, sample members are selected randomly. In this random selection, a starting point is fixed. The sample is created when the members are selected from the fixed intervals.
In the given excerpt, systematic sampling method has been used. Here, the sample has been created by selecting every third listed phone member. The interval has been created between in the sample size.
The equation of this line is y = 7x + 3. What would happen to the graph if the equation was changed to y = 2x + 6?
Answer:
From the graph,
The line y = 7x + 3 is represented by a red line with y-intercept (0, 3)The line y = 2x + 6 is represented by a blue line with y-intercept (0, 6)it is clear that the slope and y-intercept have been changed.
Step-by-step explanation:
The slope-intercept form of the line equation
y = mx+b
where m is the slope and b is the y-intercept
Given the equation of a line
y = 7x + 3
comparing with a slope-intercept form of the line equation
y = mx+b
Here,
The slope = m = 7
y-intercept = b = 3
Now, the equation changed to y = 2x + 6
y = 2x + 6
comparing with a slope-intercept form of the line equation
y = mx+b
Here,
The slope = m = 2
y-intercept = b = 6
Thus, if the equation was changed to y = 2x + 6, the slope and y-intercept also get changed from m = 7 to m = 2 and b = 3 to b = 6 respectively.
The lines of both equations is also attached.
From the graph,
The line y = 7x + 3 is represented by a red line with y-intercept (0, 3)The line y = 2x + 6 is represented by a blue line with y-intercept (0, 6)it is clear that the slope and y-intercept have been changed.
Evaluate the expression for a = 3, b=12 , and c = 4.
8ab over 2bc
Answer:
1
Step-by-step explanation:
8*12=96
96*3=288
4*12=48
48*2=96
96/96=1
Answer:3
Step-by-step explanation:
Im assuming you meant 8ab/2bc
So adding all the numbers you'll have
8x3x12/2x12x4
You first reduce the 12 in the fractions making it
8x3/2x4
and then you reduce the 8 and 2 making it 4
so you'll have
4x3/4
One last time you reduce the two fours making the
answer: 3
ITS DUE IN LIKE 5 MINUTES PLEASE HELP
Jesse and Amir were assigned the same book to read. Jesse started reading on Saturday, and he is reading 30 pages a day. Amir didn't start until Sunday, but he is reading 35 pages a day.
How many days will it take Amir to catch up to Jesse, and how many pages will they each have read?
Answer the questions to solve this problem using a system of equations.
You will use substitution to solve this system. Which variable will you substitute for and why? Show the equation that results from the substitution. Write your answer in the space below.
5. Solve the system of equations. Show your work. Write your answer in the space below.
I need help ASAP
Answer:
it will take 1/5 of a day for Amir to catch up to Jesse
Step-by-step explanation:
30x = 35x - 1
30x - 35x = - 1
-5x = -1
-5x/-5 = -1/-5
x = 1/5
Answer: brainliest pls
1. y = 35x
2. y = 30x + 1
3. y = 35x
y = 30 x + 1
4. Its more convenient to substitute y because It's easier.
35x = 30(x + 1)
5. 35x = 30x + 1
35x = 30x + 30
35x -30x = 30
5x = 30
x = 6 (30/5 = 6)
35 x 6 = 210 (y)
6. Both people have read 210 pages and it takes amir 6 days to catch up.
Step-by-step explanation:
Mr. Harris has 54.8 acres of land. Mr. Fitz has 0.35 times as many acres as Mr. Harris has. How many acres of land does Mr. Fitz have?
Answer: 19.8 acres
Step-by-step explanation:
multiply 54.8 by .35 to get 19.18
2.
In an annual function of a school every student has to participate either in sport or
in music. Out of 180 students, if 120 participate in sport and 40 participate in both
activities, find,
(i) how many students participate only in music?
(ii) Represent the above information in a Venn-diagram
Answer:
1.) 60 students
11.) kindly check attached picture
Step-by-step explanation:
Given that:
Total number of students = n(Total) = 180
Number who participate in sport = n(Sport) = 120
Number who participate in both = n(Sport n Music) = 40
Number who participate only in Music =?
Let number who participate in Music = x
Hence, n(Music only) = x - 40
n(Sport only) = 120 - 40 = 80 students
Summing all should give us n(total)
n(sport only) + n(sport n music) + n(music only) = 180
80 + 40 + (x - 40) = 180
80 + 40 + x - 40 = 180
80 + x = 180
x = 180 - 80
x = 100 students
Therefore,
n(Music only) = x - 40 = 100 - 40 = 60 students
Help help it’s geometry I need help
Answer: X = 57.5
Step-by-step explanation:
3x - 65 + x + 15 = 180
4x - 50 = 180
4x = 230
x = 57.5
Answer:
3x-65 degrees
Step-by-step explanation:
Since the angles are vertical angles, y should equal the same value of the corresponding angle.
The first line of the passage includes a
to introduce a
section and help readers locate it easily,
that
CELL PHONE POLICY
Devices Supplied by the Company
The use of company supplied devices must be limited to
work-related correspondence. They should not be used
for personal communication.
Personal Cell Phones and Devices
Employees are encouraged to limit their use of personal
cell phones and other devices during business hours.
The passage also includes
introduce more specific topics.
The passage is organized according to a
y sequence
Answer:
Step-by-step explanation:
Answer: 1. heading and subheading
2. subheading
3. point-by-point
Step-by-step explanation:
What is the ratio
18 vocabulary words learned in 2 hours; 27 vocabulary words learned in 3 hours
Answer:
I believe the answer would be 9
Step-by-step explanation:
I am sorry if I am wrong let me know.
Use compatible numbers to estimate the quotient.
522 divided by 6 please help!!!
If you bought a stock last year for a price of $79, and it has gone down 8.7% since then, how much is the stock worth now, to the nearest cent?
Answer:
72.13
Step-by-step explanation:
If you bought a stock last year for a price of $79, and it has gone down 8.7% since then, how much is the stock worth now, to the nearest cent?
Answer:
67.55 rounded to the nearest cent.
Step-by-step explanation:
The answer is 67.55 because since 100% minus 8.7% is 85.5% and 85.5% of 67.55 is 67.55 rounded.
A video game system and several games are sold for $580. The cost of the games is 3 times as much is a cost of the system. Find the cost of the system and the cost of the games. 
Answer:
The game system is 145, and the games cost 435.
Step-by-step explanation:
4x = 580
580/4=145
145x3=435 which is the cost of the games.
145 is the cost of the game system.
Give the solution to the system.
-3x + 2y = 3
2x + y = -2
(_,_)
Answer:
(-1, 0)
I will solve your system by substitution.
(You can also solve this system by elimination.)
2x+y=−2;−3x+2y=3
Step: Solve2x+y=−2for y:
2x+y+−2x=−2+−2x(Add -2x to both sides)
y=−2x−2
Step: Substitute−2x−2foryin−3x+2y=3:
−3x+2y=3
−3x+2(−2x−2)=3
−7x−4=3(Simplify both sides of the equation)
−7x−4+4=3+4(Add 4 to both sides)
−7x=7
−7x
−7
=
7
−7
(Divide both sides by -7)
x=−1
Step: Substitute−1forxiny=−2x−2:
y=−2x−2
y=(−2)(−1)−2
y=0(Simplify both sides of the equation)
PLSSS HELPSSSSSSSSSSS
what is 10 times 1 5 in simplest form?
Answer:
150
Step-by-step explanation:
There is no way to write 150 in simplest form
that is the only way to write it unless you 2ant to write it like this 150/1
Carly has already jarred 19 liters of jam and will jar an additional 7 liters of jam every day.
How much jam did Carly jar if she spent 6 days making jam? Write and solve an equation to
find the answer.
Answer:
61
Step-by-step explanation:
7×6 = 42
42+ 19 = 61 Sorry if I'm wrong I tried
Suppose a random sample of 50 college students is asked if they regularly eat breakfast. A 95% confidence interval for the proportion of all students that regularly eat breakfast is found to be 0.69 to 0.91. If a 90% confidence interval was calculated instead, how would it differ from the 95% confidence interval
Answer:
The 90% confidence interval would be narrower than a 95% confidence interval
Step-by-step explanation:
From the question we are told that
The 95% confidence interval is 0.69 to 0.91.
Generally the width of a confidence interval is dependent on the margin of error
Generally the margin of error is mathematically represented as
[tex]E = Z_{\frac{\alpha }{2} } * \frac{\sigma }{\sqrt{n} }[/tex]
Here we see that
[tex]E \ \ \alpha \ \ Z_{\frac{\alpha }{2} } [/tex]
Here [tex]Z_{\frac{\alpha }{2} } [/tex] is the critical value of half of the level of significance .
This value increase as the value of confidence level increase and vise versa
So for 90% confidence interval , the confidence level is 90% , hence the value of [tex]Z_{\frac{\alpha }{2} } [/tex] will decrease which will in turn decrease the value of E , hence the width of the interval will reduce
So the 90% confidence interval is narrower than a 95% confidence interval when the sample proportion or sample mean is constant
Pedro bought two cars, one for ₱600,000.00 and the other for ₱400,000.00. He sold the former at a gain of 10% and the latter at a loss of 12%. What percentage of the total investment was his gain or loss?
Answer:
Pedro had a gain of 1.2%
Step-by-step explanation:
Percentages
Pedro bought two cars. One for $600,000 and the other for $400,000.
He sold the first car at a 10% profit. Thus the gain was:
$600,000 * 10 / 100 = $60,000
He sold the other car at a 12% loss. Thus the loss was:
$400,000 * 12 / 100 = $48,000
The total gain or loss was $60,000 - $48,000 = $12,000
Since it's positive, the total balance is at gain.
The total investment was $600,000 + $400,000 = $1,000,000
The total gain is a percentage of the total investment of:
$12,000 / $1,000,000 * 100 = 1.2%
Pedro had a gain of 1.2%
A grocery store sells steak for $6.10 per pound. What would be the cost of 2 lb of steak?
Answer: 12.20
Step-by-step explanation:
because if 6.10 is the amount for one pound, then if u need 2 pounds, then multiply 6.10 with 2.
What is the relationship between vectors u = ⟨1, 0⟩ and v = ⟨0, –3⟩?
The vectors form an acute angle of approximately 48°.
The vectors form an acute angle of approximately 71°.
The vectors are orthogonal because the angle between them is 90°.
The vectors form an obtuse angle of approximately 132°.
Answer:
C) The vectors are orthogonal because the angle between them is 90°.
Step-by-step explanation:
got it right on edge :)
The vectors are orthogonal because the angle between them is 90°. Option C is correct.
What exactly is a vector?A vector is a quantity with a magnitude, and direction that follows the law of vector addition.
Given data;
u = ⟨1, 0⟩
v= ⟨0, –3⟩
The angle between the vector is found by the formula as;
[tex]\rm cos \theta = \frac{u,v}{|u||v|} \\\\ cos \theta = \frac{(1 \times 0) + (0 \times -3)}{\sqrt{1^2+(-0^2)+\sqrt{0^2+(-3)^2}}} \\\\ cos \theta = 1 \\\\ \theta = cos^{-1}1\\\\ \theta = 90^0[/tex]
Hence option C is correct.
To learn more about vectors, refer;
https://brainly.com/question/13322477#SPJ2
#SPJ2
6. The measure of angle Q is 70 degrees. Find the measure of angle P.
Р
Q
R
Answer:
angle P measures 40 degrees
Step-by-step explanation:
triangle with 2 equal sides has 2 equal angles also (isosceles triangle)
if angle Q is 70, then R is 70
sum of all interior angles of a triangle is 180; therefore, angle P must be 180-140
PLEASE HELPPP ME ITS DUE TODAY
Answer:
Randall: 44, Amy: 35
Step-by-step explanation:
Four years ago, their age added up to 71. Since four years have passed and they've each grown four years older since then, their ages added up together is 79. Here is the equation for Amy: x + (x + 9) = 79. We can simplify to get 35. Now we add 9 to 35 to get Randall's age. So, Amy's age is 35 and Randall's age is 44, and 35 + 44 = 79.
If the population proportion is 0.90 and a sample of size 64 is taken, what is the probability that the sample proportion is more than 0.89
Answer:
0.60515
Step-by-step explanation:
Given that:
Population proportion p = 0.9
Sample size = 64
Probability that sample proportion is more Than 0.89
P(p" > 0.89)
(p" - p) ÷ sqrt(p(1 - p) /n)
P(Z > p")
P(Z > (0.89 - 0.9) ÷ sqrt(0.9(1 - 0.9) /64))
P(Z > (-0.01) ÷ sqrt(0.9 * 0.1) / 64))
P(Z > (-0.01) / sqrt(0.00140625))
P(Z > - 0.26667) = 0.6051
Using the Z probability calculator :
P(Z > - 0.26667) = 0.60515
Darren graphs the linear equations y=-2/5x+3 and 2x+5y=15. The graph look identical so he believes that the equations represent the same line. What mathematical argument can he construct to show that the two forms are equivalent?
The slope and the intercept of both lines are the same. Because of that, the lines are identical.
What is an equation of the line?An equation of the line is defined as a linear equation having a degree of one. The equation of the line contains two variables x and y. And the third parameter is the slope of the line which represents the elevation of the line.
Given that Darren graphs the linear equations y=-2/5x+3 and 2x+5y=15. Write both equations in the slope-intercept form and compare.
The general form of the equation of the line is:-
y = mx + c
y=-2/5x+3
Solve the equation to form their general form.
2x+5y=15.
5y = 15 - 2x
y = ( 15 / 5 ) - 2 / 5x
On comparing the two lines it is observed that the lines are having the same slope and intercept.
Therefore, the slope and the intercept of both lines are the same. Because of that, the lines are identical.
To know more about an equation of the line follow
brainly.com/question/18831322
#SPJ2
Find the area of a regular octagon with side lengths of 17.2 m and an apothem length of 20.8 m.
Answer:
Pentagon a = 4.9 in. s = 7.1 in. /l ;/ >cvr'-. ~ j-?.1· '19~~. 5) Octagon a = 20.8 m s= 17.2m. ,4 ~;.>a-rt. ::: i, 17. z • t~f "g. ~ :::::, l'/?1 ,0 nt z, ... What is the length of the apothem to the nearest whole number
Step-by-step explanation:
Pentagon a = 4.9 in. s = 7.1 in. /l ;/ >cvr'-. ~ j-?.1· '19~~. 5) Octagon a = 20.8 m s= 17.2m. ,4 ~;.>a-rt. ::: i, 17. z • t~f "g. ~ :::::, l'/?1 ,0 nt z, ... What is the length of the apothem to the nearest whole number
What is the approimate volume of the cylinder? Use 3.14 for pie
Answer:
150.72
Step-by-step explanation:
8 x 6 x 3.14 = 150.72
Answer:
150.72
radius times pi
then you have the value of the inside
times it by the height
and you have the volume
Mai is making personal pizzas. For 4 pizzas, she uses 10 ounces of cheese. How much cheese does she use for each pizza? At this rate, how much cheese will she need to make 15 pizzas?
Answer:
vkigiots88558s,utt8z85a85a5s85t8s84
Answer:
a. She uses 2.5 ounces per personal pizza
b. At this rate, she will need 37.5 ounces of cheese to make 15 pizzas
Step-by-step explanation:
a. 10/4= 2.5
b. (2.5)x15= 37.5
Subtract 8 feet from 9 yards, 1 foot.
7 yards, 1 foot
1 yard, 1 foot
6 yards, 2 feet
6 yards, 1 foo
Answer:
6 yards 2 feet
Step-by-step explanation:
3 feet per yard making 9 yards and one foot = 28 feet
subtract 8 feet = 20 feet
6 yards 2 feet