Answer:
I think the answer(s) are m = -3 and/or m = 1.5 because they both hit the lines.
(sorry if I'm wrong or this wasn't helpful) 
Step-by-step explanation:
Three ways to find the slope of a line:
1. You may have two points  (
x
1
,
y
1
)  and  (
x
2
,
y
2
)  (often one or both of these points may be intercepts of the  x  and/or  y  axes). The slope is given by the equation  
           y
2
−
y
1

m  =  --------------                   (<- that's supposed to be a fraction btw)
           x
2
−
x
1
2. You may have a linear equation that is either in the form or can be manipulated into the form
y  =  m
x
+
b
.
In this case the slope is  m  (the coefficient of  x
).
3. If the line is a tangent to another function, you may have (or be able to determine) the slope of the tangent as the derivative of the function. Normally in this case the derivative is a function expressed in terms of  x  and you need to substitute the value of  x  into this function for the required location.
<3 Enjoy,
     Dea