Question

I'll Fan and Medal!!! PLEASE HELP!!!
A line goes through the point (–2,3) and has a slope of –4. What is the y-intercept of the line?

Answer 1

So you must be studying the slope/intercept equation of a line

you recognise
y = mx + b ?

Answer 2

yes. I just don't know how to set it up.

Answer 3

so - what does the value of m represent in that equation?

Answer 4

not. sure. I missed like 3 days of the class, because I was sick. And the notes my friend gave me make no sense.

Answer 5

this is a basic equation that you will need for nearly all questions on straight lines.

It is important that you learn it for yourself - if I just tell oyu it won't sink in.

Look here and find out what m is in the equation y=mx+b

http://www.coolmath.com/algebra/08-lines/07-equations-of-lines-slope-intercept-form-01

Answer 6

m represents slope.

Answer 7

ok good

now the question tells you that the slope is -4

so we can begin to write the equation

y= -4x+b

OK so far?

Answer 8

Yes.

Answer 9

so you know the slope and you know that the point
(–2,3) lies on the line so

when x = -2 y=3

so can oyu write my equation from above, but substitute 3 for y , and -2 for x

Answer 10

y=mx+b
3=(-4)(-2)+b
What's b?

Answer 11

b is what you are trying to find (the intercept)

so if we tidy up the equation we get
3= 8 +b

so subtract 8 from each side to find b

Answer 12

b=-5

Answer 13

good

so the total equation is this

y= -4x-5

and the graph looks like this:



well done