Question

For the data in the table, does y vary with x? if it does write an equation for the direct variation.
x y
2 5
6 15
18 45

a. yes y=0.4x
b. yes y=10x
c. yes y=2.5x
d. no y does not vary directly with x

Answer 1

Please, you have to conjecture, as relationship between x and y, the subsequent formula:
y=mx+q,
where m and q are the unknow coefficient to be determined. In order to that, please you can substitute the coordinates of the first two points in the relationship above, so you will get a system of two equation in two unknow quantities m and q. For example If I use the coordinates of the first point, I get:
5=2m+q (1)
whereas if I use the coordinates of the second point I get:
15=6m+q (2)
Now equations (1) and (2) are a system, please try to solve that system and write your solution for m and q

Answer 2

@Bpgrace the second step is to check if the tird point, namely (18, 45) verify your resultant relationship

Answer 3

oops (18,45) verifies...I have made a grammar error, sorry