Use 'disputable' to describe matters open for debate or discussion in various contexts. Whether homework is beneficial for students is disputable.
Pro Tip 2/3
Context Sensitivity
'Disputable' often implies that a topic is not settled and opinions on it may vary widely. The benefits of a low-carb diet are disputable among nutritionists.
Pro Tip 3/3
Avoid Certainty
Don't use 'disputable' when referring to facts or conclusions widely accepted or proven by evidence. That the Earth orbits the sun is not disputable.