Answer:
-4/17
Step-by-step explanation:
The slope of a line refers to the rate of change. First, put the equation into y-intercept form to clearly identify the slope.
[tex]20x+85y=120\\\\20x+85y-20x=120-20x\\\\85y=-20x+120\\\\\frac{85y}{85}=\frac{-20x+120}{85}\\\\y=-\frac{4}{17}x+\frac{24}{17}[/tex]
The coefficient next to the x is -4/17. Therefore, the rate of change (slope) of the line is -4/17.