pls help :,l - 100 points if u answer this jawn

DeBrown Corporation offers employees a retirement plan based upon
the following formula. The retiree will get 2% of the average of the
fi nal three year salaries times the number of years employed by the
company. Suppose an employee’s last three years of salaries are A, B,
and C, and the employee worked at DeBrown for D years. Write the
algebraic expression that represents the employee’s yearly pension.