excess depn & pup – mini questions

Hi,

question 2 – page 202

i have worked out the first lots of depreciation which is fine,

however in the answers there is an 8000 & 9000, which i can not work out where this has come from?

i have used your calculation to get the correct answer – 5000/5 remaining years = 1000
5000-1000 = 4000

however i just wanted to know where the 8k & 9k come from so i can understand this better?

thank you!