Place a checkmark in the columm below the correct direct variation equation, if possible

I'll break this into four parts, one for each table.

Part 1

To see if we have a direct variation, we divide each y value over its corresponding paired x value. So we compute y/x. If we get the same result for each column, then we have a direct variation.

Column 1 = y/x = 2/20 = 0.025

Column 2 = y/x = 4/30 = 0.1333 approximately

We don't get the same y/x value, so we don't have a direct variation.

Part 2

Same idea as before

Column 1 = y/x = 30/2 = 15

Column 2 = y/x = 90/6 = 15

Column 3 = y/x = 105/7 = 15

Column 4 = y/x = 165/11 = 15

We get the same result each time, so the constant of proportionality is k = y/x = 15.

Therefore the direct variation equation is y = 15x.

All direct variation equations are in the form y = kx.

Part 3

Column 1 = y/x = 54/3 = 18

Column 2 = y/x = 90/5 = 18

Column 3 = y/x = 126/7 = 18

Column 4 = y/x = 162/9 = 18

We get the equation y = 18x, which is a direct variation

Part 4

Column 1 = y/x = 15/1 = 15

Column 1 = y/x = 30/4 = 15/2 = 7.5

We get different values, so table 4 is not a direct variation.