ANSWER:
Zero
STEP-BY-STEP EXPLANATION:
The slope can be calculated with the following formula
[tex]m=\frac{y_2-y_1}{x_2-x_1}[/tex]Replacing the points A (4, 6) and B (-2, 6):
[tex]m=\frac{6-6}{-2-4}=\frac{0}{-6}=0[/tex]Therefore the answer is zero.