What should be added to 1/4 to get 4/9?

What should be added to 1/4 to get 4/9?

Let x should be the required number.

ATQ,

(1/4)+x=4/9

Or, (1+4x)/4=4/9

Or, (1+4x)=16/9

Or, 4x=16/9-1

Or, 4x=(16-9)/9

Or, 4x=7/9

Or, x=7/36