3. Give two systems of equations that would be easier to solve by substitution
than by elimination. Then give two systems that would be easier to solve with
elimination. Finally, explain how you decide whether to use elimination or
substitution to solve a system.

Answers

Answer 1

Answer:These techniques for elimination are preferred for 3rd order systems and higher.  They use "Row-Reduction" techniques/pivoting and many subtle math tricks to reduce a matrix to either a solvable form or perhaps provide an inverse of a matrix (A-1)of linear equation AX=b.  Solving systems of linear equations (n>2) by elimination is a topic unto itself and is the preferred method.  As the system of equations increases, the "condition" of a matrix becomes extremely important.  Some of this may sound completely alien to you.  Don't worry about these topics until Linear Algebra when systems of linear equations (Rank 'n')  become larger than 2.

explanation Step-by-step explanation:ust to add a bit more information, "Elimination" Can have a variety of other interpretations.  Elimination techniques typically refer to 'row reduction' to achieve 'row echelon form.'  Do not worry if you have not heard of these terms.  They are used in Linear Algebra when referring to "Elimination techniques"

Just to add a bit more information, "Elimination" Can have a variety of other interpretations.  Elimination techniques typically refer to 'row reduction' to achieve 'row echelon form.'  Do not worry if you have not heard of these terms.  They are used in Linear Algebra when referring to "Elimination techniques"

 

Gaussian Elimination

Gauss-Jordan Elimination

LU-Decomposition

QR-Decomposition

 

These techniques for elimination are preferred for 3rd order systems and higher.  They use "Row-Reduction" techniques/pivoting and many subtle math tricks to reduce a matrix to either a solvable form or perhaps provide an inverse of a matrix (A-1)of linear equation AX=b.  Solving systems of linear equations (n>2) by elimination is a topic unto itself and is the preferred method.  As the system of equations increases, the "condition" of a matrix becomes extremely important.  Some of this may sound completely alien to you.  Don't worry about these topics until Linear Algebra when systems of linear equations (Rank 'n')  become larger than 2.

 

Substitution is the preferred method for 2 equations in 2 unknowns.  The constants are unimportant other than having a non-zero determinant.  It is always easy to find multiplicative factors using LCMs of one variable or the other to allow substitution into the other equation:

 

Example:

 

4X + 5Y = 9

5X -  4Y = 1

 

Notice that 20 is a LCM of either the X or Y variable.  So multiply the first by 4 and the second by 5 and then adding the two (Y's will drop out allowing for substitution)

 

4(4X + 5Y = 9)

5(5X -  4Y = 1)  

 

Multiplying to produce the LCM factors:

 

16X + 20Y = 36

25X -  20Y = 5

 

Adding the equations

 

41X = 41

X = 1

 

Substitution into either equation yields

Y = 1


Related Questions

I need help with this geometry math assignment I been struggling and I need help on it very fast and it is due today so please help me out I will mark you Brainly and I’m stress and worry.Also please help me I need the answer I try my best

Answers

Answer:

12a. (-6, -6)

12b. 17

13a. y = [tex]\frac{-1}{2}[/tex] x + [tex]\frac{3}{2}[/tex]

13b. 2

Step-by-step explanation:

12a. Using the midpoint formula:

[tex](\frac{-9-3}{2} ,\frac{2-14}{2} )[/tex] = [tex](\frac{-12}{2} , \frac{-12}{2})[/tex] = (-6, -6)

12b. Using the Distance formula:

d = [tex]\sqrt{(3 - (-9))^{2} +( 14 - 2)^{2} }[/tex] = [tex]\sqrt{(12)^{2}+(12)^{2} }[/tex] = [tex]\sqrt{144 + 144}[/tex] = [tex]\sqrt{288}[/tex]

= 12[tex]\sqrt{2}[/tex] or 17

13a. x + 2y = 3

2y = 3 - x

y = [tex]\frac{-1}{2}[/tex] x + [tex]\frac{3}{2}[/tex]

13b. The perpendicular slope is 2

Help with my homework please

Answers

Answer:

I hope it was helpful to you

I it was helpful follow me

Answer:

12×5=60

60÷2=30

area=30cm²

Step-by-step explanation:

A cube with a side length of 6 feet is sliced diagonally such that it passes through the three vertices shown in the figure. Which describes the cross section?

A cube. A cross section is a triangle that touches 3 corners of the cube.
a triangle with 3 equal sides measuring 6 feet
a triangle with 3 equal sides measuring greater than 6 feet
a triangle with only 2 equal sides measuring 6 feet
a triangle with only 2 equal sides measuring greater than 6 feet

Answers

Answer:

C)  a ttiangle with only 2 sides measuring 6 feet

Step-by-step explanation:

The cross section is a triangle with three equal sides measuring more than 6 feet.

What is a cube?

A cube is a solid three dimensional shape with 6 faces or squares of equal length.

Analysis:

The diagonal of one face of the cube forms right angle triangle with the adjacent sides of that face of the cube.

So using Pythagoras to find length,

[tex]diagonal^{2}[/tex] = [tex]6^{2}[/tex] + [tex]6^{2}[/tex]

[tex]diagonal^{2}[/tex] = 36 + 36

[tex]diagonal^{2}[/tex] = 72

diagonal = [tex]\sqrt{72}[/tex] = 8.48 feet. Which is same form the remaining two diagonals forming the triangle.

Therefore the cross section is a triangle with three equal sides with length greater than 6  feet.

In conclusion,  the cross section is a triangle with three equal sides with length greater than 6  feet.

Learn more about cubes: brainly.com/question/1972490

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What is the median of the following set of data?
0.6, 0.5, 0.9, 0.4, 0.3, 0.7, 0.2

Answers

Answer:

Median: 0.5

Step-by-step explanation:

Arrange the following set of data from least to greatest:

0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.9

then find the middle number (the median).

since there are seven numbers in the data set we divide it, by doing this:

{0.2, 0.3, 0.4} 0.5 {0.6, 0.7 0.9}

Therefore, the median for the data set is 0.5!

(i'm sorry if you don't get it, i'm just bad at explaining)

idk this pls help don’t understand

Answers

Answer:

95º

Step-by-step explanation:

i think

It is 95 degrees because it is at a vertical angle from

Choose the system of equations that matches the following graph:

3x + 4y = 24
3x + y = −3

3x + 4y = 24
3x − y = 3

3x − 4y = −24
3x + y = −3

3x − 4y = −24
3x − y = 3

Answers

One of the lines passes through points (0, 6) and (-4, 3). Hence the equation is given by:

(y - 6)/(x - 0) = (3 - 6)/(-4 - 0)

(y - 6)/x = -3/-4 = 3/4

4(y - 6) = 3x

4y - 24 = 3x

3x - 4y = -24

The other line passes through points (0, -3) and (1, 0). Hence the equation is given by:

(y - (-3))/(x - 0) = (0 - (-3))/(1 - 0)

(y + 3)/x = (0 + 3)/1

y + 3 = 3x

3x - y = 3

Therefore, the system of equations representing the graph is:

3x - 4y = -24

3x - y = 3

Was this helpful?

I need to know answer to the quest

Answers

Answer:

1 and 1/16 gallons

Step-by-step explanation:

1/1/16 that’s the answer

aiden and 5 friends went out for chicken and soda. the total cost of the soda was $7. if each person paid $14, what was the total cost of the fried chicken

Answers

Answer:

63$...I think

Step-by-step explanation:

if there was 5 friends and each paid 14$ the total must have been 70$. However, since the soda was 7$, then if you take away 7$ from the total, then the chicken must have been 63$

I don't know, man. Math isn't really my strongest suit, but I hope this helps :D

Answer:

$77

Step-by-step explanation:

Each person paid $14

Aiden+5 friends= 6 people

$14×6= $84

total cost of soda was $7

$84-$7= $77

Help me for 1000 points

Answers

Answer:

20 pounds

Step-by-step explanation:

2.5 times 8 would be 20 pounds

Answer:

The answer is 20

Step-by-step explanation:

Because if you do 2 1/2x8 you get 20

Hope This Helps

if the manufacturer makes 1500 beanbag chairs per day, how many of those chairs would they expect to be understuffed?​

Answers

Answer:

15 will be understuffed

Step-by-step explanation:

Answer:75 would be under stuffed

Step-by-step explanation:

PLEASE HELP 30 POINTS!!!!!
Is this an enlargement or a reduction? How do you know?
(One point for stating if it is an enlargement or reduction. Two points for explaining how you know that.)

Answers

Answer:

Reduction. The coordinates that are prime is the smaller, inside triangle. Since the triangle is shrinking and becoming smaller, its a reduction.

Step-by-step explanation:

The figure above the x-axis is the preimage. The figure below the x-axis is the image. Which transformation produced the image?
A.
reflection across the x-axis
В.
reflection about the origin
C.
rotation 90° clockwise about the origin
D.
rotation 90° counterclockwise about the origin

Answers

Answer:

Option B.

Step-by-step explanation:

From the picture attached, figure above the x-axis is the pre-image and below the axis is the image.

Let's choose a point B of the image having coordinates (0, 2).

When the point B is transformed, coordinates of the point B' is (0, -2)

And the rule for this transformation will be,

(x, y) → (-x, -y)

This rule shows the reflection of pre-image over the origin.

Option (B). will be the answer.

Answer:

B

Step-by-step explanation:

yes

Find the measurements of ∠ and ∠.

Answers

Answer:

m∠ FAE = 20°, m∠ CAD = 60°

Step-by-step explanation:

If you take a look at the picture below, this explanation proves that the measure of FAE ⇒ 20°, and m∠ CAD = 60°;

IT'S FINALS TIME- PLEASE HELP

Answers

Answer:

It is 42 degrees! Hope this helps!

Step-by-step explanation:

Consider the expression below


Which two numbers will go with this equivalent expression in factored form


? { 10+ ? ]


5 7 25 30 35 40

Answers

This one is my real answer 5{10+3]=40 The other one you can use for extra this one 5{10+25]=35

A cylinder has a radius of 12m and a height of 30m. Find the surface area and volume

Answers

Answer:

Surface Area: 1008π OR 3166.73

Volume: 4320π OR 13,571.68

Step-by-step explanation:

Surface Area Equation:

2πrh+2πr^2

Work:

2π (12) (30) + 2π12^2

2π(360) + 2π(144)

720π + 288π

1008π OR 3166.73

Volume Equation:

πr^2h

Work:

π12^2 (30)

π144 (30)

4320π OR 13,571.68

A deck of cards contains 52 different cards. The probability of drawing a queen of hearts is 1/52. What type of probability is this ? A. Theoretical probability B. Empirical probability C. Random probability D. Fractional probability​

Answers

Answer:

Theoretical Probability

Step-by-step explanation:

This is because as a theory, without doing any testing, this is what is expected. A theoretical probability is based on the mathematics.

There are 90 penguins in a zoo. There are two types - Humboldt and Emperor.
52 are female, of these 6 are Emperor penguins.
There are 5 male Emperor penguins.
Use this information to complete the frequency tree.
Humboldt penguins
Emperor penguins
Male
Female
Humboldt penguins
Emperor penguins

Answers

Answer:

See below.

Step-by-step explanation:

Humboldt penguins; 90 - (5 + 6) = 79.

Emperor penguins: 5 + 6 = 11.

Total Male: 90 - 52 = 38.

Male Humboldt penguins: 38 - 5 = 33.

Total Female: 52.

Female Humboldt penguins: 52 - 6 = 46.

We can solve this by creating an attribute table.

                                 HUMBOLDT          EMPEROR          TOTAL

MALE                             33                          5                         38

FEMALE                         46                          6                         52

TOTAL                            79                           11                        90

What is attribute table?

An attribute table is a  database or tabular file containing information about a set of geographic features, usually arranged so that each row represents a feature and each column represents one feature attribute.

Learn more about attribute table here

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THIS PERSON NEED HELPPPPPP! BRAINLIEST IF U ANSWER NICELY AND A WHOLE 28 POINTSS!

Answers

Answer:

Step-by-step explanation:

Step 6: as the line on the line graph moves from left to right, the line falls.

step 7: (idk)

Answer:

See answer for Step 6 below.

Step 7: the slope is "-1/2" (negative 1/2)

Step-by-step explanation:

Step 6: A negative slope means that as the value of the coordinate "x" increases,the value of the coordinate "y" decreases, and the rate of change for points on the line is therefore negative. The line goes "DOWN" as you read the graph from left to right.

In order to calculate the slope, we can use the triangle defined by the points (0, 5), (4, 3)  and (0, 3) as shown in the attached image:

Where the "run" is from 0 to 4 , that is:  4 - 0 = 4

and the rise is negative (from 5 to 3: that is 3 - 5 = -2

Therefore, the rise over the run becomes: -2 / 4 = -1/2

PLEASE I REALLY NEED HELP ILL 5 STAR THANK AND BRAINLIEST YOU!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Last year, the school library had a total of x books. Over the summer, the library acquired another 37 books and now has a total of 1,950 books. Which equation could be used to find x, the number of books the library had last year?
A.
1,950 + x = 37
B.
x + 37 = 1,950
C.
x - 37 = 1,950
D.
37x = 1,950

Answers

Answer:

its B

Step-by-step explanation:

Answer:

Step-by-step explanation:

The answer is B. X+37=1,950

please answer with the:

axis of symmetry

vertex

(explain how if you can)

Answers

Answer:

x=1

Step-by-step explanation:

X= means that it is the vertical line on that number, so x=1 would be the vertical lines going through 1, which would be in the middle of the parabola, thus having symmetry

Answer:

axis of symmetry: x = 1

vertex: (1,-4)

Step-by-step explanation:

You can find the axis of symmetry for this parabola by looking at the x coordinate for the vertex or buy looking at the graph for which x value that you can draw a line through and have symmetry on both sides.

For the vertex, you just look for the maximum of minimum (for this graph its minimum) point on the parabola.

Please mark me as brainliest if this helped you. Thank you!

Increase £180 by 10%

Answers

Answer:

£ 198

Step-by-step explanation:

10% of 180 = 18

180 + 18 = 198

Answer:

£198

Step-by-step explanation:

[tex]180 \times \frac{10}{100} \\ = 18 [/tex]

[tex]180 + 18 = 198[/tex]

hope this helps

brainliest appreciated

good luck! have a nice day!

Choose the true statements regarding the comparison of the two data sets. Check all that apply,
The SAT versus IQ graph has a slightly stronger association than the GPA versus IQ graph,
There is a negative association between GPAs and SAT scores.
A high IQ causes a high GPA.
The slope of the trend line for the SAT versus IQ graph is greater than the slope of the trend line for the GPA
versus iQ graph

Answers

Answer:

yes the answer is correct it is A and D

Step-by-step explanation:

Edge 2020-2021

Answer:

A & D

Step-by-step explanation:

Picture below⬇️

Filomena is deciding between two mortgages for her new home. The first
mortgage is an 80/20 mortgage with interest rates of 4.75 and 7.525%,
respectively. The second mortgage is a 30-year mortgage with a 5.25% and a
$42.56 monthly PMI. If the house price is $100,000, which mortgage payment
will be lower initially, and by how much?

A. 30-year mortgage by $33.28
B. 30-year mortgage by $39.55
C. 80/20 mortgage by $37.25
D. 80/20 mortgage by $55.01

Answers

Answer:c.

Step-by-step explanation:

Which point on the coordinate plane is at (1,3)?

A) point A

B) point B

C) point C

D) point D


Answers

Answer:

b

Step-by-step explanation:

Start at the origin.  Go the right 1 unit.  Then go up 3 units

You are at Letter B

The answer is point B

I need help on the second one

Answers

Answer:

See explanation

Step-by-step explanation:

First, let's convert feet to miles.

[tex]\dfrac{63,756 \text{ feet}}{1}\cdot \dfrac{1 \text{ mile}}{5,280 \text{ feet}}=12.075\text{ miles}[/tex]

Next, let's convert minutes to hours.

[tex]\dfrac{70 \text{ minutes}}{1}\cdot \dfrac{1\text{ hour}}{60\text{ minutes}}=\dfrac{7}{6}\text{ hours}[/tex]

Finally, let's find the unit rate.

[tex]\dfrac{12.075\text{ miles}}{\frac{7}{6}\text{ hours}}=10.35\text{ mph}[/tex]

Hope this helps!

What is the missing value from the table

Answers

The answer is going to be 12.

Answer:12

Step-by-step explanation:In the table you can see that the numbers given under Y

Are in a pattern counting by sixes so if you do 6×3 you get 18 for missing the second one so we do 6×2 which equals 12 and that is the answer.

A cardboard box is 18 feet long, 7 feet wide, and 6 inches high. What is the is closest to the volume of the box in cubic YARDS? 20 points

Answers

Answer:

The volume of the box is [tex]2.33\ \text{yards}^3[/tex].

Step-by-step explanation:

We have,

Length of a cardboard box is 18 feet

Width of cardboard box is 7 feet

Height of a cardboard box is 6 inches

The conversion from one units and another is as follows :

1 foot = 0.334 yards

18 feet = 6 yards

7 feet = 2.334 yards

1 inch = 0.0277 yards

6 inches = 0.1667 yards

Now,

Length, l = 6 yards

Width, b = 2.334 yards

Height, h = 0.1667 yards

The box in the form of cuboid. The volume of a cuboid shaped object is given by :

[tex]V=l\times b\times h[/tex]

Plugging all the values, we get :

[tex]V=6\times 2.334\times 0.1667\\\\V=2.33\ \text{yards}^3[/tex]

So, the volume of the box is [tex]2.33\ \text{yards}^3[/tex].

Whats the answers for questions 3​

Answers

Answer:

?

Step-by-step explanation:

A $25.00 shirt is on sale. how much does it cost at
10% off
20% off
40%off
50%off
do all % please
if u get them right i need help with more

Answers

Answer50% = 12.5

Step-by-step explanation:

Answer:

Im too lazy to put here

Step-by-step explanation:

10% off --> 90% the actual cost

25 x 90% = 22.50

$22.50

20% off --> 80% the actual cost

25 x 80% = 20.00

$20.00

30% off --> 70% the actual cost

25 x 70% = 17.50

$17.50

40% off --> 60% the actual cost

25 x 60% = 15.00

$15.00

50% off --> 50% the actual cost

25 x 50% = 12.50

$12.50

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