Doubts – Answering the AFM paper

Hi,
I just have a few doubts when it comes to answering the questions, especially in regarding the investment appraisal:

Investment Appraisal tends to have a lot of workings which could be quite time-consuming so is it okay if I use short words instead of writing the entire thing?
For eg:
Variable Cost – VC
Selling Price – SP
Plant and Machinery – Pl. & Machinery OR P&M
Depreciation – Dep.
Exchange Rate – Ex.Rate
Tax Allowable Deprecation – Tax
Tax – Tx

Will this trick cost me my marks for the AFM exam?

Please let me know if my approach is incorrect and if it is incorrect, are there any short words acceptable by the examiner team?

Thank you so much!