We have been given an equation
. We are asked to find constant of proportionality from our given equation.
We know that two directly proportional equations are in form
,where y is directly proportional to x and k is constant of proportionality.
Let us rewrite our given equation by cross multiplying as:
![2y=9x](https://img.qammunity.org/2021/formulas/mathematics/high-school/8ix5ukmz3b495cm2i9ttq1vmjjjelymmet.png)
Now we will divide both sides of equation by 2.
![(2y)/(2)=(9x)/(2)](https://img.qammunity.org/2021/formulas/mathematics/high-school/sg8h48y9kqf613gdjlmi5hrqepbpasjljf.png)
![y=(9)/(2)x](https://img.qammunity.org/2021/formulas/mathematics/high-school/qdsn6nvi8c2bi5frbnbekektvba3v88yvl.png)
We can see that our equation is in form
and constant of proportionality is
.