To find the slope, let's first convert it to the form y=mx+b
3x-9y=4
Subtract 3x from each side
-9y= -3x+4
Divide each side by -9
y= 3/9x - 4/9
3/9 can be simplified into 1/3
y= 1/3x-4/9
It is now in the form y=mx+b. We know that m is the slope. Therefore, the slope of the line is 1/3