Question

Tell whether the ordered pair is a solution of the linear equation.
(-3, 1)
x=y=-2
x+5y=2
I will gladly appreciate if you help, because I don't know how to do this at all. So can you explain the step for me please. And thank you.

Answer 1

please help

Answer 2

help plz

Answer 3

x=y=-2 has too many equal signs

Answer 4

is it x+y=-2 or is it x = y + -2, or is it x = y+2

Answer 5

x+y=-2 my bad

Answer 6

ok first solve for y in x+y=-2

x+y=-2

y = -2 - x

y = -x - 2

Answer 7

Just need to know how to do this so I can figure out the other problems as well.

Answer 8

now plug this into the second equation

x+5y=2

x+5(-x - 2)=2 ... replace y with -x - 2 (this is possible since y = -x - 2)

x - 5x - 10 = 2

I'll let you finish

Answer 9

and Oh yeah I was suppose to put in a graph as well.

Answer 10

so you will need to solve both for y

Answer 11

y = -2 - x

y = -x - 2 How come you flipped it like that?

Answer 12

x+5y=2

5y=2 - x

5y = -x + 2

y = -x/5 + 2/5

y = -1/5x + 2/5

Answer 13

because the general form is y = mx+b and you can compare it easier that way

Answer 14

oh yeah...hahhaha I remember....that XD equation.

Answer 15

you use that to help you graph

Answer 16

need help

Answer 17

ok where are you stuck

Answer 18

Fraction part

Answer 19

you mean this

y = -1/5x + 2/5

right?

Answer 20

Sorry I'm confused how to do this problem to be honest

Answer 21

you graph the two equations

where they cross is where your solution is at

Answer 22

yseh how did you get the fraction

Answer 23

well you can use 0.4 in place of 2/5 if you want

better yet, do you have a graphing calculator?

Answer 24

nope. But its ok. I know how to do the calculation. Just ned to know the step hwo to do this problem and that's it.

Answer 25

Give me two minutes to understand what you wrote ok? Because I am tired and did soooo much homework today. XD Stressed pretty much. XD

Answer 26

y = -1/5x + 2/5

y = (-1/5)(0) + 2/5

y = 0 + 2/5

y = 2/5

So when x = 0, y is y = 2/5, which means you have one point (0, 2/5)

Answer 27

alright

Answer 28

For the x- 5x-10=2 is it-4x-20=2?

Answer 29

x- 5x-10=2 turns into -4x - 10 = 2

not sure where you got the 20 from

Answer 30

-4x - 10= 2 becomes -4x=12then its x=3?

Answer 31

-4x = 12

x = -3

Answer 32

not x = 3

Answer 33

Was a typo. Was about to fix it.

Answer 34

i gotcha

Answer 35

Why do you have to plug the first equation to the second equation

Answer 36

because that's one method of getting rid of one variable so you can solve for the other

Answer 37

notice you went from 2 variables (x and y) to just one variable (x) and you solved for it

you would then use that solution for x to find the solution for y

Answer 38

So the fraction part would equal 0.2 and -1.44?

Answer 39

wait it would be 2.14?

Answer 40

I don't really know how to graph it on the graph. XD

Answer 41

we found x to be x = -3

remember how we solved for y?

well we found that y = -x - 2

so...

y = -x - 2

y = -(-3) - 2 ... plug in x = -3 (replace x with -3)

y = 3 - 2

y = 1

Answer 42

this means that the solution is (-3, 1)

Answer 43

visually, the two graphs will cross at the point (-3, 1)

Answer 44

Then what is the point for the second equation?

Answer 45

Is the second equation for another x and y?

Answer 46

we used it to find x

Answer 47

no there's only one solution in this case

Answer 48

For them to cross?

Answer 49

yes, you need two lines to have them cross

Answer 50

at a single point

Answer 51

That's what I mean

Answer 52

btw, once you find x, you can use either equation that has y in it to plug in x = -3 and solve for y

Answer 53

What do you do after y= -1/5 + 2/5?

Answer 54

well if you wanted to graph, you would solve each for y

Answer 55

then you would plug in any x value you want to get a corresponding y value

Answer 56

this will give you a point that lies on the line

Answer 57

do it twice and you have two points in which you can use to graph

Answer 58

Just show me how to do it. plez........................draw it XDD

Answer 59

I really need to get this done XD

Answer 60

ok say you wanted to graph y = 2x + 7

you would plug in x = 0 to get y = 2(0) + 7 = 7

so one point is (0, 7)

when x = 1, y = 2(1) + 7 = 9

another point is (1,9)

Answer 61

so to graph y = 2x + 7, you plot the two points (0,7) and (1,9)

then you draw a straight line through them

Answer 62

So one line for the first equation and another one line for the second quation right? If its only one equation you use it for 2 lines?

Answer 63

TO see if it crosses and get a single point answer

Answer 64

you got it

Answer 65

But where did you get the 0 though? o.O

Answer 66

I just randomly picked an x value (a small x value to make things easy)

Answer 67

x could be 2, 7, 11, whatever you want it to be

Answer 68

just make sure it is within the window of view

Answer 69

So its kinda like a free for all in away DXD

Answer 70

pretty much

Answer 71

x could be a million, but that's way off the charts, so we won't go there

Answer 72

That kinda makes more sense to me now. XD I just need a little more explaination XD I may have to ask you give me another 2 minutes

Answer 73

alrigt

Answer 74

alright*

Answer 75

Let me ask you a question though. How do you get a line from a fraction again? XD

Answer 76

That one confuses me the most

Answer 77

say x = 0

when x = 0, then y is...

y = -1/5x + 2/5

y = (-1/5)(0) + 2/5

y = 0 + 2/5

y = 2/5

Answer 78

so when x = 0, y is y = 2/5

Answer 79

2/5 is the same as 0.4

so when x = 0, y is y = 0.4

Answer 80

so you have the point (0, 2/5) or (0, 0.4)

Answer 81

That's what I did so the x can be anything right?

Answer 82

Or any number

Answer 83

yes, 0 is the easiest to work with though

Answer 84

mm ok

Answer 85

Do you have answer ? and can I give you the answer and tell if its correct?

Answer 86

yes I do, and I posted the answer previously

Answer 87

but tell me what you got

Answer 88

WHat was answer though?

Answer 89

what did you get? don't worry about being correct or not

Answer 90

so -3,1 and the other one is (0.4,0)?

Answer 91

(-3,1) is the only solution

Answer 92

(0,0.4) is a point that's used to help graph y = (-1/5)x + 2/5

Answer 93

but it's not the solution

Answer 94

So its not asking to make the graph then?

Answer 95

remember, these two lines only cross at one point

Answer 96

no they just want the solution

how you get the solution is up to you

Answer 97

I know...XD but you put 0, 0.4 on the graph thas what Im asking

Answer 98

you could graph, use substitution, elimination, etc etc