Using text book: Fundamentals of Corporate Finance by Brealey, Myers, & Marcus 2020, 10th edition

Income versus cash flow. Butterfly Tractors had $14 million in sales last year. Cost of goods sold was $8 million, depreciation expense was $2 million, interest payment on outstanding debt was $1 million, and the firm's tax rate was 21%.

a. would you expect the change in depreciation to have a positive or negative impact on the firm's stock price?

b. what would be the impact on net income if depreciation was $1 million and interest expense was $2 million?

c. what would be the impact on cash flow if depreciation was $1 million and and interest expense was $2 million?

please show formula work