Answer:
2 is the constant of proportionality in the equation y = 2x .
Explanation:
Definition of constant of proportionality
When two variables are directly proportional to each others .
Let us assume that u and v .
u \propto vu∝v
Than the equation becomes u= kv
Where k is called the constant of proportionality .
Thus in the question x and y are proportional variables .
i.e
y \propto xy∝x
y = kx
Where k is called the constant of proportionality .
Compare the equation y = kx with y=2x .
Thus
k = 2
Therefore 2 is the constant of proportionality in the equation y = 2x
the explanation is not mine only the answer