Question

I have a question about the slope....







In the slope formula y=mx+b what is the difference between the y and the b and how do I know when to plug it in to the y or b?

Answer 1

b is y-intercept a point where line cross y-axis(there would be only one )
y = just y-coordinate
you don't need to plug anything for y

Answer 2

Example problem: Line A has slope of -5/3 and passes through the point (-2,7). WHat is the x-intercept of line A?

Answer 3

yes y=mx+b so replace m with -5/3
y=-5/3x+b
now you have x y value (-2,7) x=-2
y=7
substitute x and y for their solve for b(y-intercept )

Answer 4

I just don't understand what to plug into the y or b.... like if they ask it passes through the line then what do i do? use it for the y or b?

Answer 5

x-intercept is a point where line cross the x-axis
when y =0
after you find y-intercept substitute y for 0

Answer 6

Like what are some examples of when i have to use it for y or b? what do they have to say for me to know where to replace it?

Answer 7

when they say passes through the points (x,y) then you have to find b

Answer 8

so replace the b with the number they say it passes through the points?

Answer 9

or the y

Answer 10

replace with y not b (b is y-intercept )

Answer 11

hmmm okay

Answer 12

here is an example
slope =2 passes through (4,3)
\[\huge\rm \color{reD}{y}=mx+b\]\[(4,\color{ReD}{3})\]

Answer 13

So in what cases do i replace the b (y-intercept) what kind of problems do they have to ask for

Answer 14

then statement would be like this
slope is 3 and ***Y-INTERCEPT =5

Answer 15

they would use the *y-intercept ) word

Answer 16

hmmm okay

Answer 17

maybe this helps??:

y = 3x + 2
is a formula to "find y" if you are told x.
you then put the x and y together as a package (x,y)
for example, if x is 1, y will be 5 (do you see how?) and (1,5) is the "package" which is just a way to say the point (1,5) is on the line.

does that part make any sense?

Answer 18

the next idea is we can (in theory) find all the points on the line using its formula
that can be useful and the reason we want a formula rather than a long boring list of (x,y) pairs

Answer 19

hmmmm i mean thats easy i'm just hving a hard time understand when to substitute the y or b

Answer 20

i know why you r confused
but y-intercept is the specific point where line cross the y-axis which is also one of the y value
but they will always use the y-intercept word for b