I got this question on Khan accadamy so when I check it I will put the answer here too. Which equation has a constant of proportionality equal to 2? Choose 1
(Choice A)

y=\dfrac{10}{5}xy=
5
10

xy, equals, start fraction, 10, divided by, 5, end fraction, x

(Choice B)
B
y=\dfrac{2}{2}xy=
2
2

xy, equals, start fraction, 2, divided by, 2, end fraction, x

(Choice C)
C
y=\dfrac{2}{4}xy=
4
2

xy, equals, start fraction, 2, divided by, 4, end fraction, x

(Choice D)
D
y=\dfrac{22}{2}xy=
2
22

x