Answer:
1) July 1, 2020, sale of land
Dr Notes receivable 1,419,656
Cr Land 590,900
Cr Discount on notes receivable 517,436
Cr Gain on sale of land 311,320
Discount on notes receivable $1,419,656 - $902,220 = $517,436
Gain on sale of land $902,220 - $590,900 = $311,320
2) July 1, 2020, service revenue
Dr Notes receivable 402,150
Cr Service revenue 342,218.69
Cr Discount on notes receivable 59,931.31
annual interests = $402,150 x 3% = $12,064.50
discount on notes payable = present value of annual interest = $12,064.50 x 4.9676 (PV annuity factor, 12%, 8 periods) = $59,931.31