+314 I am soooo confused about this:
How can you tell if a slope is negative or positive? For instance in this question (btw I know what to fill in the second blank):
How can I tell? I NEED A SIMPLE EXPLANATION IM DUMB.
+590 If the line is going up, it's positive. If the line is going down, it's negative.
That's probably the simplest answer...
+118677 Ghosty, do you really think your answer makes sense.
All lines that are not horizontal or vertical go up on one end and down on the other end ://
+590 My brain needs a few adjustments... Making too many mistakes in math. It might take a while for me to get back on track. Sorry everyone. 
+118677 Hi,
Firstly you are not dumb, :)
Dumb people do not bother to ask good questions :)
First .. is the gradient positive or negative. ??
Lines go for ever, if you think about any line,
it may eventually be in the top right corner where the + is in which case the gradient will be positive.
OR
it will eventually be in the top left corner where the - is in which case the gradient will be negative.
So does your line have a positive or a negative gradient ?
Now, I think your line goes through the two points (0,-9) and (3,3)
Draw a right angled triangle between these two known points. One side has to be parallel to the x axis and the other parallel to the y axis, like I have done.
gradient is rise/run To get from the bottom point to the top one you have to rise 12 and run along 3
SO the gradient is + (because the line heads off to the top right corner) 12/3 = +4
The y intercept is -9, you said you already knew that.
b=-9
m=4
line: y=mx+b
this line y=4x+-9
y=4x-9
I have redrawn you graph so I can explain better
+9673 When the line looks like a backslash "\", its slope is negative.
When the line looks like a slash "/". it slope is positive.
