What are three different methods for solving systems of equations and when would you use each one?

Answers

Answer 1

The first method is substitution. This is when the x or y value that is known is substituted into one of the equations. This should be done when you can easily see or find the x or y value.

Example: x = 3, and x + 8y = 30.

The x was given in the first equation (x = 3), and can therefore be substituted into the other equation to find y.

The next method is elimination. This is when you add the two systems together and eliminate either the x values or the y values. This should be done when there are opposite signs of the same number in both equations.

Example: y - 3x = 24, and 2y + 3x = 7

In the first equation you have -3x, and in the second you have 3x. If you were to add the two equations, the x values would cancel out and you would be left with:

y + 2y = 24 + 7

And then you could solve for y.

The last method is to graph both equations and to see at which point the lines intersect.

Related Questions

Write an equation of the line that passeg through (8, 1) and is perpendicular to the line 2y + 4x = 12

Answers

Answer:

y=1/2x-3

Step-by-step explanation:

First, let's put the line into slope intercept form

2y+4x=12

subtract 4x from both sides

2y=-4x+12

divide by 2

y=-2x+6

the slopes of perpendicular lines are negative and reciprocal. If you multiply the slopes of the lines together, the result is -1. Therefore, to find the slope of the perpendicular line, use this formula:

-2m=-1

divide by -2

m=1/2

so the slope of the perpendicular line is 1/2

here is the new line so far:

y=1/2x+b (b is a place holder)

now, since the line passes through the point (8,1), it means that (8,1) is a solution of the line. So we can substitute it into the equation

1=1/2(8)+b

1=4+b

subtract 4 from both sides

-3=b

so the line is y=1/2x-3

Hope this helps!

I WILL GIVE BRAINLIEST PLS HELP ME I NEED HELP, Samantha drew a scale drawing of the floor area covered by her couch on a grid that represented the floor area in her living room. She used the scale 1 cm = 1.25 ft.
To the nearest hundredth of a square foot, What is the floor area covered by Samantha's couch?

Answers

Answer:

It Represents An actual length of 2 ft.

Step-by-step explanation:

One-third of a painting job takes 24 hours. How long will it take to complete the entire job?

Answers

72 hours. 1/3 of the Job is 24 hours, multiply 24x3

Find the measure of the given angle.

Answers

Answer:

angle UWT=150 degrees

Step-by-step explanation:

angle UWT=360-80-130

angle UWT=150 degrees

I need help with this problem ASAP

Answers

Answer:

y=-7

Step-by-step explanation:

horizontal line means that it doen't cross the x axis, so you just ignore the x value

The pie chart shows the favorite retail clothing store of
a group of teenagers.
About what percentage of teenagers prefer ForLess?
v%
About what percentage of teenagers prefer BuyMore?
%
About what percentage of teenagers prefer Silklt?
%

Answers

Answer:

I think it is 75% on this question

Answer:

1. 40

2. 30

3. 10

Step-by-step explanation:

What is m ZSRW?

- 18
- 54
- 126
- 108

Answers

Answer:

126

Step-by-step explanation:

Angle SRW is supplementary to (2x + 18)º and (3x)º, that is, they add up to 180º.

Finding angles in function of X:

Since angles (2x + 18)º and (3x)º are opposite by vertex R, they have the same measure. So

[tex]3x = 2x + 18[/tex]

[tex]x = 18[/tex]

[tex]3x = 3(18) = 54[/tex]

Angle SRW:

Supplementary with 54. So

54 + SRW = 180

SRW = 180 - 54 = 126

So 126 is the answer.

I really need help with this

Answers

answer: 1. 1/52 2. 2 3.
explanation

Find the area of the shape.
19 yd
5 yd
6 yd
9 yd
The area is

Answers

Answer:

Step-by-step explanation:

Answer:

84 yd2

Step-by-step explanation:

Can someone please help me, Im stuck on this question.

Answers

Answer:

D. 14

Step-by-step explanation:

4^2 - 2 (evaluate)

16 - 2 (calculate)

Answer is D! Hoped it helped!

write 0.125 as a simplest fraction and percent.

Answers

Answer:

12½% 0.125 1/8

Step-by-step explanation:

8.5x-5+2.6x simplify the expression

Answers

I am pretty sure the answer is 11.1x-5

You leave a 10% tip on a $30 dinner bill. Find he amount of the tip and add it to
$30. How much is your total bill, including the tip? *

Answers

33 dollars. The tip is 3 dollars, and that to 30 dollar dinner bill and the whole bill will be $33.

so since you're only doing 10% of 30, you get 3

add 3 to 30 and you get 33

what is the solution to the division problem below?

Answers

Answer:

there is no division problem

Step-by-step explanation:

Answer:

This may be the work

Step-by-step explanation:

A circular "No Parking" road sign has a diameter of 26 inches.
Which measurement is closest to the area of the sign-in square inches?

Answers

Answer: The answer is 530.66

Step-by-step explanation:

I took the test and 81.64 is wrong, It's 530.66

The area of the road sign in the circular shape of diameter 26 inches is closest to 530.66 in².

What is the area of a circle?

The area of the circle is pi times the square of the radius of a given circle.

The area of the circle = [tex]\pi r^2[/tex]

A road sign "No Parking" is given in a circular shape of diameter 26 inches. we need to find the area of the sign.

The diameter of the circle is 26 in so, the radius will be half of the diameter which will be 13 in.

Now, the area of the circle = [tex]\pi r^2[/tex]

the area of the circle = 3.14 × 13 × 13

= 530.66 in²

Hence, the area of a circle of diameter 26 inches is equal to 530.66 in².

Learn more about the area of a circle here:

brainly.com/question/27120842

#SPJ3

1. Find the area. *
5 ft
5 ft
16 ft
16 ft

Answers

Answer:

25 cm square and 256 cm square

Step-by-step explanation:

What is the discounted price for a watch that is regularly $58.00 and 30% off?

Answers

Answer:

$40.60

Step-by-step explanation:

please help!! If ED=5, then determine the length of AB

Answers

Answer:

AB equals 25

Step-by-step explanation:

1( you take ED and the 5 and say of 5.

2( then you count all the letters that stand for numbers and count them.

3) after you count them how many ever there are then you take that number which was 5 too.

4(after you find that number which is number 5 you multipliy 5 and 5.

5(after you multipliy then you should get 25 because 5x5 is 25.

And there you go thats the answer step by step.

Erik added 23 new contacts to phone list He had to delete 18 old contacts before could add any more. He now has a total of 100 contacts. Let c represent how many contacts had on phone list before updated it. Write an equation and then solve for c.

Answers

Answer:

c-18+23=100

c=95

Step-by-step explanation:

to prove that the answer is 95 subtract the 18 that she deleted to get 77 then add the 23 that she added after deleting 18 and you get 100

Answer:

c+23−16=100

c=93

Step-by-step explanation:

Need help ASAP will give brainliest

Answers

Answer:

the second one :)

Step-by-step explanation:

show that KLMN is a parallelogram

Answers

Is the awnsers two?
or is it 3

classify the following triangle. check all that apply.

Answers

Answer:

Scalene and acute

Step-by-step explanation:

Scalene and acute is the answers

im doing decimals greatest to least and i need help with number 12 and 13

Answers

(I know there isnt any real problem here to solve, but heres a tip on how to solve greatest to least with decimal problems)

1. Just because a number looks big, doesn't mean it is big

Example: 1.00000000000001 < 1.1

just look at the numbers ^ and dont just hastily read it over assuming that 1.1 is smaller because it "has less digits"

2. Negative numbers are... opposite. and they are less than positive numbers

-3.4 > -4.1

Why is this? Well, if you look on a line, with the point 0 in the middle, you can see that -3.4 is not as far away from 0 as -4.1 is. So the idea is to apply opposite logic for negative numbers

I hope these tips helped!! :D

Answer:

12) 6.32, 6.318, 6.23, 6.108

13) 1.345, .654, .645, .456

Step-by-step explanation:

I need to know the whole thing please help

Answers

Answer:

a) A student travelling to school on public transport: 15/52 or 0.231

b) A student walking to school: 16/52 or 0.308

c) A student not cycling to school: 43/52 or 0.827

Step-by-step explanation:

Total people = 52

Travel Method Frequency

Public Transport 12

Car 15

Cycle 9

Walk 16

Find the relative frequency of.

The formula used will be: [tex]Relative\:Frequency=\frac{Given\: Frequency}{Size\: of\: sample \:space}[/tex]

a) A student travelling to school on public transport:

Given Frequency: 12

Size of sample space: 52

Apply formula: [tex]Relative\:Frequency=\frac{Given\: Frequency}{Size\: of\: sample \:space}[/tex]

Fraction = 12/52

Decimal = 0.231

b) A student walking to school

Given Frequency: 16

Size of sample space. 52

Apply formula: [tex]Relative\:Frequency=\frac{Given\: Frequency}{Size\: of\: sample \:space}[/tex]

Fraction = 16/52

Decimal = 0.308

c) A student not cycling to school.

We will consider all students except those who cycle.

12+15+16 = 43

Given Frequency: 43

Size of sample space. 52

Apply formula: [tex]Relative\:Frequency=\frac{Given\: Frequency}{Size\: of\: sample \:space}[/tex]

Fraction = 43/52

Decimal = 0.827

x + 3y – 2z = 3
-x – 2y + z = -2
2x – 7y + z = 1

Answers

Answer:

x + 3y – 2z = 8

-x – 2y + z = 12

2x – 7y + z =7

this answer is fake

Step-by-step explanation:

x + 3y – 2z = 3

-x – 2y + z = -2