The symbol [tex] \leq [/tex] means x is less than or equal to a certain value (in this case, 4).
Your first step is to find 4 on the x axis, because your inequality is for x (This eliminates the first 2 answers, as they solve for y). You know x can be equal to 4, so you make a solid, vertical line through that value (the line is vertical because the y value can be anything because it is not in the inequality).
Next, x can be less than 4, not greater, so you shade to the left of the line (this is were the smaller numbers are).
It is always wise to test a point to make sure you shaded in the correct direction. (0, 0) is a nice simple one. You plug in your value(s)... and 0 is indeed less than or equal to 4, so you know you shaded in the correct direction.
Hope this helps.
