Tell whether the relation is a direct variation. Explain. х
-9
-1
5
у
90
10
-50
This is not a direct variation, because it cannot be written in the form y = kx

This is a direct variation, because it can be written as xy = -10
where k = 0.

This is a direct variation, because it can be written as y=-1/10x, where k=-1/10

This is a direct variation, because it can be written as y = -10x
where k = -10.

This cannot be determined

Please help me out this is a important question