Find the slope of the line that contains these points (-2,5) (-4,11)

The first thing you have to do is:

subtract: 11-5

Then subtract: -4-(-2)
 
then you put it as a fraction:  6/-2 or -3

That -3 would be considered the slope.

So now you have: y=-3x+ b

So what you have to do is plug in one of the points into the equation to find out what b is.

For example:  11 = -3(-4) + b 
                                   11=12 + b
                                    -12   -12
                                        b = -1
So the answer is: y = -3x -1