see below
Step-by-step explanation:
A relation is "direct variation" if it can be written in the form ...
y = kx
for some constant k. That value can be found from any line* in a table that has direct variation:
k = y/x
_____
* A table with direct variation may have the entry (x, y) = (0, 0). That table entry cannot be used to find the value of k. If either x or y is zero, the other must be also if the variation is direct.