can you explain the highlighted solution, why i only took these?

P11.4 Comco Tool Corp. records depreciation annually at the end of the year. Its policy is to take a full year's depreciation on all assets that are used throug year and depreciation for half a year on all machines that are acquired or disposed of during the year. The depreciation rate for the machinery is io\%, appliee straight-line basis, with no estimated scrap or residual value. The balnnoe of the Machinery account at the beginning of 2023 was \$172,300; the Accumulated Depreciation on Machinery account had a balance of $72,900. T machinery accounts were affected by the following transactions that occurred in 2023 : Jan. Machine no, 38, which cost $9,600 when it was acquired on June 3,2016 , was retired and sold as scrap metal for $600. 15 Feb. Machine no, 81 was purchased. The fair value of this machine was $12,500. It replaced two machines, nos, 12 and 27 , which were traded in on the new 27 machine. Machine no, 12 was acquired on February 4,2011 , at a cost of $5.500 and was still cairied in the accounts, although it was fully depreciated and no in use. Machise no. 27 was acquired on June 11,2016 , at a cost of $8,200. In addition to these two used machines, Connco paid $9.000 in eash. Apr. Machine no. 54 was equipped with electric controls at a cost of $940. This machine, originally equipped with simple hand controls, was purchased on 7 December 11, 2019, for \$1,800. The new electric controls can be attached to any one of several maelines fa the shop. 12 Machine no, 21 was ropaired at a cost of S72o after a fire caused by a short circuit in the wiring burbed out the motor and damaged certain essential parts. July Machines 25, 26, and 41 were sold for 33.100 cash. The purchase dates and cont of these machines wete as follown: Instructions Depreciation expense =$139,00010%$13,900 Depreciation expense =$41,24010%1/2$15,9622.062 Total depreciation expense P11.4 Comco Tool Corp. records depreciation annually at the end of the year. Its policy is to take a full year's depreciation on all assets that are used throug year and depreciation for half a year on all machines that are acquired or disposed of during the year. The depreciation rate for the machinery is io\%, appliee straight-line basis, with no estimated scrap or residual value. The balnnoe of the Machinery account at the beginning of 2023 was \$172,300; the Accumulated Depreciation on Machinery account had a balance of $72,900. T machinery accounts were affected by the following transactions that occurred in 2023 : Jan. Machine no, 38, which cost $9,600 when it was acquired on June 3,2016 , was retired and sold as scrap metal for $600. 15 Feb. Machine no, 81 was purchased. The fair value of this machine was $12,500. It replaced two machines, nos, 12 and 27 , which were traded in on the new 27 machine. Machine no, 12 was acquired on February 4,2011 , at a cost of $5.500 and was still cairied in the accounts, although it was fully depreciated and no in use. Machise no. 27 was acquired on June 11,2016 , at a cost of $8,200. In addition to these two used machines, Connco paid $9.000 in eash. Apr. Machine no. 54 was equipped with electric controls at a cost of $940. This machine, originally equipped with simple hand controls, was purchased on 7 December 11, 2019, for \$1,800. The new electric controls can be attached to any one of several maelines fa the shop. 12 Machine no, 21 was ropaired at a cost of S72o after a fire caused by a short circuit in the wiring burbed out the motor and damaged certain essential parts. July Machines 25, 26, and 41 were sold for 33.100 cash. The purchase dates and cont of these machines wete as follown: Instructions Depreciation expense =$139,00010%$13,900 Depreciation expense =$41,24010%1/2$15,9622.062 Total depreciation expense