I searched for the following question and the answer was provided by way of excel. However, the formula for PVAF does not work and I would prefer the long hand answer as I am trying to understand the priciples of finance. There are other examples in the list of question, but none that show how to calculate the answer with immediate $100\%$ depreciation. Thanks for your assistance.

Gluon Inc. is considering the purchase of a new high pressure glueball. It can purchase the glueball for $$70,000$ and sell its old low$-$pressure glueball, which is fully depreciated, for $$12,000.$ The new equipment has a $10-$year useful life and will save $$16,000$ a year in expenses. The opportunity cost of capital is $9\%,$ and the firm$$s tax rate is $21\%.$ What is the equivalent annual saving from the purchase if Gluon can depreciate $100\%$ of the investment immediately.I searched for the following question and the answer was provided by way of excel. However, the formula for PVAF does

not work and I would prefer the long hand answer as I am trying to understand the priciples of finance. There are other

examples in the list of question, but none that show how to calculate the answer with immediate $100\%$ depreciation.

Thanks for your assistance.

Gluon Inc. is considering the purchase of a new high pressure glueball. It can purchase the glueball for $$70,000$ and sell

its old low$-$pressure glueball, which is fully depreciated, for $$12,000.$ The new equipment has a $10-$year useful life and will

save $$16,000$ a year in expenses. The opportunity cost of capital is $9\%,$ and the firm's tax rate is $21\%.$ What is the

equivalent annual saving from the purchase if Gluon can depreciate $100\%$ of the investment immediately.