A machine equipment has an initial purchase price of $20000$$ $,$ an estimated scrap value of $2000$$ and an economic life of $5$ years

a$)$ The Straight Line Method $.$

b$)$ The Sum$-$of$-$the Years'$-$ Digits Method $.$

c$)$ Double Declining Balance Method

Calculate the annual depreciation and residual values of the machine equipment according to the above methods?