Question 602456
What's nice here is that the y coordinates are the same horizontal line. 
So essentially these two points can be placed on a number line at -1 and 3. The distance between -1 and 3 is 3-(-1) = 3+1 = <font color="red">4 units</font>. 


So the distance between (-1, 6) and (3, 6) is <font color="red">4 units</font>