Question

Help with slope again? I need to figure out how to graph a line if I only have something like this y =4x+2 for example

Answer 1

I don't understand...

Answer 2

y = mx + b

m = slope
b is y-intercept

Answer 3

the y-intercept is where you put your first point....in your case at y = 2 you would put a point okay?

Answer 4

Okay

Answer 5

maybe a side by side comparison will help too

y =4x+2
y =mx + b

so YOUR slope is 4...and y-intercept is 2

so after you put your point at y = 2

you deal with the slope

Answer 6

would you agree that .....4...can be written as 4/1?

Answer 7

Yes

Answer 8

okay good.....now remember

slope = rise / run

rise (where you go in the y-direction)
run (where you go in the x-direction)

you have slope as 4/1 right?

so if slope is

rise 4
---- and you have ----
run 1

how far in the y-direction will you travel?...and then how far in the x-direction?

Answer 9

you travel 1 in the x-direction and 4 in the y-direction?

Answer 10

correct!

so now

starting at the point you plotted...at y = 2


you go up 4 units.....then over to the right 1 unit.....
****4 up because it is a positive 4 right? and over to the right 1 because it is also positive right?****

then you can make a point where that ends...and then do it again....and eventually...connect those dots and make your line

Answer 11

Okay is this right? It doesn't seem like it >.<

Answer 12

@johnweldon1993

Answer 13

yeah that is correct...why doesn't it seem right?

Answer 14

I think it's my line :b It's so crooked >.<

Answer 15

lol better?

Answer 16

actually no yours is wrong...you only went up 3 in the y-direction

Answer 17

I should'vegone up how many instead?

Answer 18

but you had the right idea....remember you were supposed to go up 4?

Answer 19

Ohh that's right

Answer 20

"
starting at the point you plotted...at y = 2


you go up 4 units.....then over to the right 1 unit.....
****4 up because it is a positive 4 right? and over to the right 1 because it is also positive right?****

"

remember that?

Answer 21

Yes, I don't know why I didn't go four :/

Answer 22

Do you think you could help me with another one?

Answer 23

no problem....but you do have the general idea!

Answer 24

The equation is y=2x+3 this time and this is how I graphed it...also I was wondering, what do I do to complete the rest of the graph? like do I do it negatively? so go down 3 and go 2 to the left?

Answer 25

take it step by step......what are you supposed to do first? to determine where you start on the graph?

Answer 26

Yes, so I determined that I start at 3 since that's the y intercept ooh :b I need to start at 3 first

Answer 27

haha there you go lol...and after that you dont worry about that 3 anymore do you?

you ONLY care about the slope...which is?

Answer 28

Which is 2/1 so now I got up 2 and go to the right 1 :D

Answer 29

correct.......

now...before you had the right idea...and good job recognizing that...

if you wanted to go in reverse

the slope being 2/1

what is -2/-1? the SAME thing right?

just in a different direction

so yes you can go down 2 and to the left 1 as well to make more points

Answer 30

So it's this :D

Answer 31

perfect :)

Answer 32

Okay can we do 1 last one?

Answer 33

sure why not lol...but you're getting good at it

Answer 34

:D Thanks :D This time with a slope of y=1/5x+4

Answer 35

I know first I go up 4

Answer 36

Wait this is just like all the other ones lol

Answer 37

you mean you plot a point at 4 right?

Answer 38

Only I start with a fraction, so I go up 1 and move to the right 5 right? And yes, I mean put a point at 4 but I have to go up 4 to do that so I said go up 4 :b I should've said plot a point at 4 though xD

Answer 39

and yes it's just like the other ones

and yes you are correct about the slope as well....so the graph will look like?

Answer 40

Like this :D

Answer 41

you are now a master :D

Answer 42

Whoop! :D

Answer 43

I know I keep saying this..could we do one last one? I promise it's the last one :b

Answer 44

lol great job and feel free to message me or fan me if you need anymore help :)

Answer 45

or just ask another one :P lol sure :)

Answer 46

:D Thanks haha, this time it's 3x+4y=8 so I'm not sure how to graph it

Answer 47

ha....this one...you need to work at it first...this is what we call the "standard form" of a line

you need to convert it into slope intercept form

so change

3x+4y=8
to
y = mx + b

can you?

Answer 48

****hint...notice how y is by itself in the equation you want****

Answer 49

So...it'll be
3x + 4y = 8
-3x -3x
4y = -3x + 8
/4 /4

y = -3x/4 + 8/4
y = -3/4x + 2
is that right?

Answer 50

again...you are a master :)

Answer 51

:D Math isn't so bad..yet :b

Answer 52

lol no of course it isn't :D

Answer 53

since 3 is negative, do I go down 3 instead?

Answer 54

here's a hint

try graphing it with the -3 and the / 4
and then try it with +3 and the / -4

what do you get?

Answer 55

This is with -3 and the /4

Answer 56

.......waiting for it .....

Answer 57

lol...*****suddenly a realization will come over you*****........lol