Answer:
y=1/2x
Explanation:
we know that
A relationship between two variables, x, and y, represent a proportional variation if it can be expressed in the form
or
In a proportional relationship the constant of proportionality k is equal to the slope m of the line and the line passes through the origin
Verify each case
case 1) we have
y=2/3x + 4
This line not passes though the origin (because for x=0 the value of y is not zero)
therefore
The equation is non proportional
case 2) we have
y=(1/2)x
This line passes though the origin (because for x=0 the value of y=0)
therefore
The equation is proportional
case 3) we have
2x + 3y=7
This line not passes though the origin (because for x=0 the value of y is not zero)
therefore
The equation is non proportional