Answer:
see below
Step-by-step explanation:
Slopes of perpendicular lines are negative reciprocals of each other:
m1 = -1/m2
(m1)(m2) = -1
So, their product is -1.
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Additional comment
The rule above does not apply to horizontal and vertical lines, because the slope of a vertical line is undefined. In this problem, that is not an issue, because the lines are not aligned with the axes.
