Basically you know that 2000 is within the margin of 10001-50000, so the tax rate is 5%. From here we can multiply 40000 (the starting value) and multiply it by 0.05 (which is 5% as a decimal), so it calculates out to 2000!! Good luck :)
Since there is no graph included in the question, the most reasonable answer would be 0. The slope would be 0 because they didn't give you a graph for the question.
