Question

The slopes of perpendicular line segments are 1/2 and d/3 What is the value of d?

Answer 1

Perpendicular slopes have a product of -1, thus   $\bf \cfrac{1}{2}\cdot \cfrac{d}{3}=-1$

solve for "d"

Answer 2

Perpendicular lines have slopes that multiply to get -1
so

1/2 times d/3=-1
d/6=-1
times both sides by 6
d=-6