I just need help on 2 equations. plz help

Question

for the data in the table, does y vary directly with x? if it does, write an equation for the direct variation.
y: 4, 16, 36
x: 16, 32, 48

A: yes, y=2x
B: yes, y=4x
C: yes, y=8x
D: no, y does not vary directly with x

for the data in the table, does y vary directly with x? if it does, write an equation for the direct variation.
y: 13, 26, 39
x: 8, 16, 24

A: yes y=5x
B: yes y=10x
C: no y does not vary directly with x
D: yes y=1.625x

Answer 1

I'll do the 2nd one first.
let y = kx
for (8,13) ---> 13 = 8k, k = 13/8 = 1.625
for (16,26) ---> 26 = 16k, k = 26/16 = 1.625
for (24,39) ---> 39 = 24k, k = 39/24 = 1.625

so we have a constant value of k = 1.625
It is a direct variation, and y = 1.625x

repeat this for the first question, what do you conclude?

Answer 2

i will conclude that the answer is (D: yes y=1.625x)
thanks for teaching me how so solve these equations
it will help me a lot <3