i confus

Im supposed to write the equation that describes each line in slope-intercept form.the question is "The line that passes through (1,5) and (4,-4). now i know y=mx+b

and i found what m is (slope=-3 or -3/1). so i need to find what b is. pls help...?

I have absolutely no idea why you sent CPhill to that link.......

You have already done half the work here

y= mx+b                   m=-3

so

y=-3x+b          

Now id you put ANY point that is on the line into this equation you will get the value of  'b'.

I am going to use (1,5) but if I used (4,-4) I would get exactly the same answer.

y=-3x+b         x=1,  y=5

5=-3*1+b

5=-3 +b

8=b

so

y= -3x + 8   is the equation of the line :)

CPhill did it a different way.  There are lots of ways you can do these.  :D

You have the correct slope.....

So.....using either point and the slope......we can write the line in  point slpoe form  =

y - 5  = -3(x -1)

y = -3x + 3  + 5

y = -3x + 8

So...  "b"   = 8    [ this is the y intercept]

k no cloo wut u just did but if i get this question wrong, u have to subscribe to meh on youtube. (link is https://www.youtube.com/channel/UC2V77M0HoKjlISZmYMrZeFQ )

Could you please talk to us in English Ape4 ?

You see we are "mature" and it takes to much effort to work out text speak.  LOL

(LOL is one of the few that I have worked out and adopted )