How do you do number 4 ? can someone explain too me ?

Step-by-step explanation:

So, you're given a slope of - (2/3) and are to graph it?

Recall that slope, m, = rise / run

                                   = (change in y) / (change in x)

As the simplest possible example, start your graphing at (0,0).

Place a black dot there.  Now, starting at that dot, move your pencil point 3 units to the right; this is the change in x.  Place a dot there.  Now, starting there, move 2 units down.  Place a third dot there.  Draw a line through (0,0) and this third dot, which is (3, -2).

Let's try another example involving slope:

Let's graph y = 3x - 1.  Comparing this to y = mx + b, we see that the slope, m, is 3 (or 3/1) and the y-intercept is (0, -1).

Place a black dot at (0, -1).  Then, from this point, move 1 unit to the right and then 3 units up.  Place a black dot there, at (1, 3).  Draw a line through the two points (0, -1) and (1, 3).  

-6 + 3 = 3 - 6

c.

step-by-step explanation: