Each equation represent a proportional relationship. Choose the equation for which the constant of proportionality is 4/5

the slope goes by several names
• average rate of change
• rate of change
• deltaY over deltaX
• Δy over Δx
• rise over run
• gradient
• constant of proportionality
however, is the same cat wearing different costumes.
[tex]16x-20y=0\implies -20y=-16x\implies y=\cfrac{-16x}{-20}\implies y=\stackrel{\stackrel{m}{\downarrow }}{\cfrac{4}{5}}x \\\\[-0.35em] ~\dotfill\\\\ 25y=20x\implies y=\cfrac{20x}{25}\implies y=\stackrel{\stackrel{m}{\downarrow }}{\cfrac{4}{5}}x \\\\[-0.35em] ~\dotfill\\\\ y=0.8x\implies y=\cfrac{8}{10}x\implies y=\stackrel{\stackrel{m}{\downarrow }}{\cfrac{4}{5}}x[/tex]