Answer:
Step-by-step explanation:
The equation factors as ...
Values of x that make the factors zero are the locations of the vertical asymptotes: x = 3 and x = 9.
The answer is A !!! Good luck!
the key is to write as which can be easily seen as an area of a rectangle with one side length n and the other (n+1). That explains the rectangle made of dots - 3 x 4
Now you only have half of them because of the 1/2. So that explains the lower "triangle" of dots being greyed out - they do not count in the area (upper triangle). So the count of the dark dots corresponds to the original expression.
For n=5 you can draw a similar rectangular matrix with 5 x 6 dots. And count only the upper triangular part.