Answer:
2
Explanation:
First, put the line into y = mx + b form to find the slope (m)
x + 2y = 8
Subtract x from both sides
2y = -x + 8
Divide each side by 2
y = -1/2x + 4
So, the slope of this line is -1/2
Perpendicular lines have a opposite reciprocal slope, so the slope of a perpendicular line will be 2.