The equation of a line in slope-intercept form is given by the formula:
\[ y = mx + b \]
where \( m \) is the slope and \( b \) is the y-intercept.
Given the slope \( m = -\frac{2}{9} \) and the y-intercept \( b = 3 \), you can substitute these values into the equation:
\[ y = -\frac{2}{9}x + 3 \]
This is the equation that represents the line with the specified slope and y-intercept.