Answer:
The first option is not a direct variation
Step-by-step explanation:
When we talk of a direct variation, as one value increases, the other value increases too
Or as one value decreases, the other value decreases
A direct variation is of the form;
y = kx
k = y/x
where k is the coefficient of variation that must be a constant value all through the set of values
The values we are comparing here are the x and y values
So
let us take a look at the options;
The first option is not a direct variation
For the first option, the rate of increase is not constant;
2/6 = 1/3 , 8/12 = 2/3 , 14/18 = 7/9
for the second;
the ratio is 1 to 1
for the third;
3/6 = 1/2 ; 6/12 = 1/2; 9/18 = 1/2
for the fourth;
2/6 = 1/3, 4/12 = 1/3 , 6/18 = 1/3
