using Uber Technologies most recent $10-$K answer the following:

A$.$ Using the consolidated statements of operations, analyze the profitability of the company by preparing a common$-$size income statement for the past three years. In addition, calculate sales growth and operating expense growth for each two$-$year period presented, as well as effective tax rates for all three years.

B$.$Using the consolidated statements of stockholders$$ equity for the company, explain the key reasons for the changes in the common stock, accumulated other comprehensive income, and retained earnings accounts. Evaluate these changes.