Please show steps by step as I am not understanding

Perpetual Inventory Using LIFO Beginning inventory, purchases, and sales data for portable DVD players are as follows: Apr. 1 Inventory 65 units @ $61 10 Sale 52 units 15 Purchase 85 units @ 63 20 Sale 47 units 24 Sale 14 units 30 Purchase 29 units @ $66 The business maintains a perpetual inventory system, costing by the last-in, first-out method. Determine the cost of merchandise sold for each sale and the inventory balance after each sale, presenting the data in the form illustrated in Exhibit 4. Under LIFO, if units are in inventory at two different costs, enter the units with the HIGHER unit cost first in the Cost of Merchandise Sold Unit Cost column and LOWER unit cost first in the Inventory Unit Cost column. Schedule of Cost of Merchandise Sold LIFO Method Portable Game Players