9y - 4x - 9 = 0
Let's rewrite this function.
Add 4x to both sides.
9y - 9 = 4x
Use distributive law.
9(y - 1) = 4x
Divide both sides by 9.

Add 1 to both sides.

Note that the above function of y is in the form y = mx + c, where m is the slope and c is the y-intercept.
Here, the slope of the function is 4/9 and y-intercept is 1.