Question

Write a linear system that models the situation. The sum of two numbers is 14. Their difference is 10. I got 2+12 = 14. Help? I suck at this...

Answer 1

Okay I'm stumped.

Answer 2

Does the problem call for you to solve it?

Answer 3

I don't think so. It just says model the situation as a linear equation..

Answer 4

Maybe it's just x + y = 14

Answer 5

As a linear "system"?

Answer 6

Yes.

Answer 7

A system of equations has more than one equation.

Answer 8

That's why I don't understand this...It's weird.

Answer 9

The term linear refers to the variables having no exponents.
So, it's asking you to write those two equations using x and y

Answer 10

Don't you mean no coefficients?

Answer 11

Your first answer, X + Y = 14 is correct. You need to turn the Something minus something = 10 into a equation

Answer 12

Oh.

Answer 13

Uh x -y = 10

Answer 14

Bam. That's it!
X + Y = 14
X - Y = 10

Answer 15

Wow...

Answer 16

And yup, a linear equation has no exponents. All of it's variables are to the first power.

Answer 17

Damn I'm stupid

Answer 18

I always think the problem is going to be hard, but it's hella easy.

Answer 19

Thank You once...again.

Answer 20

You're welcome. Also, Don't ever call yourself stupid, because you're not. Don't sell yourself short. If you keep telling yourself your stupid, you'll eventually believe it.

Answer 21

I'm stupid on this one question.

Answer 22

:P

Answer 23

Okay now I'm stuck again.

Answer 24

What is an equation for one CD costing $2 more than the other? Do you know? >-<

Answer 25

Well, the first step is to assign variables, right?

Answer 26

You told me
CDA = CD2 + $2, right?

Answer 27

Well both of the two Cds equal $28

Answer 28

We can use mathematics to describe relationships between things

Answer 29

Yes.

Answer 30

What's the whole question?

Answer 31

You buy two CDs for a total of $28. One CD cost $2 more than the other.

Answer 32

-_- XC Bahh. I can't answer it.

Answer 33

? Sure you can.

Answer 34

It's asking you to write another system of equations, right?

Answer 35

Yeah.

Answer 36

First off, what's in a system of equations? What is it? And why do we use it?

Answer 37

We try to find the values of the unknown?

Answer 38

A system of equations is a list of equations. It has several equations, usually with more than one variable

Answer 39

Are you still here?

Answer 40

Yes.

Answer 41

Okay.
We use a system of equations to help solve for more than one variable.

Answer 42

Okay.

Answer 43

With one equation, X + Y = 12, it's impossible to find what X and Y are. Can you tell me why?

Answer 44

Please tell me why. ^^

Answer 45

Because we need a real number. You can't just solve it with variables?

Answer 46

Nope. Try graphing it

Answer 47

You can't.

Answer 48

unless you make up the numbers..

Answer 49

Variables exist within an equation, so we can put numbers in.

Answer 50

I think what you mean, is that there is an infinite amount of solutions, right?

Answer 51

Yeah..pretty much.

Answer 52

In the equation (X+Y = 12), if X = 3, than Y = 9, if X is 10, than Y is 2, and so on

Answer 53

You can graph these points, and it makes a straight line. The straight line represents all of the answers that work in the equation.

Answer 54

Okay. Are you telling me then I can find the slope...? rise/run right?

Answer 55

The slope is a tool. It helps us graph the line, and it tells us how quickly it goes up or down.
I'm explaining this to you, because I don't think you completely grasp graphing, or equations yet.

Answer 56

I know how to graph equations.

Answer 57

I usually use y=mx + b

Answer 58

I then graph it from there, or there are other forms I can graph from like standard form or point-slope form.

Answer 59

I undestand that you can graph. But do you understand why you graph?

Answer 60

Why do we graph?

Answer 61

We graph for a couple of reasons.

Answer 62

First off, pictures are easier to understand than really complicated formulas

Answer 63

True,

Answer 64

Next, with a graph, we can solve equations that we don't know the answer of

Answer 65

Equations? That's only useful for math!
But, remember what I said? We use math to describe how things are related

Answer 66

I'm going to give you two equations, and I want you to graph them, okay? When you graph them, you should be able to get the answer without doing any algebra.

Answer 67

You need to just plug in a few points, and then plot them.

Answer 68

X + Y = 12, and X - Y = 5

Answer 69

Graph them on the same graph.

Answer 70

(If that makes any sense :) )

Answer 71

Yeah it does. You can solve linear systems by substitution or graphing or elimination..

Answer 72

Yup.

Answer 73

Okay it's 2:08am. It's not hat I want to not learn, but I need to goto sleep now. Thanks for the lecture.

Answer 74

If you graph the two lines, they should intersect at only one point. That's the only answer that's correct.

Answer 75

:D

Answer 76

For your question, you need to write a system of equations.

Answer 77

Yeah they intersect, but I still think substitution is the easiest way out of all the methods I've learned.

Answer 78

It's the fastest. With the more complicated math, you'll suddenly love graphing

Answer 79

What itf you can't draw lines that well?

Answer 80

Erm, substitution is. And, the lines don't have to be perect.Anyway,
You buy two CDs for a total of $28. One CD cost $2 more than the other.

Answer 81

also I know I have to write linear systems but I only think I have to write two.

Answer 82

x + y = 28 I know that's one.

Answer 83

I think the other is 2 - y ...

Answer 84

One CD + 2 = another CD, right?

Answer 85

Just substitute the variables

Answer 86

No the total cost of the two equals 28 dollars.

Answer 87

I don't need to solve it..

Answer 88

Yeah. But the 2nd clause says that one cd costs two more dollars than the other

Answer 89

That's an equation.

Answer 90

Oh I wrote an expression..

Answer 91

Oh I wrote an expression..

Answer 92

Oh I wrote an expression..

Answer 93

?

Answer 94

X + 2 = Y. Truthfully, it doesn't matter what variable +2 = the other variable.

Answer 95

Must be a glitch

Answer 96

Anyway, I'm sorry I wasn't the most helpful for the equation.
God bless with your mathematic endeavors, and good night.

Answer 97

Okay

Answer 98

Ashag, are you still here? If so, go to your latest problem, and I"ll take a crack at it