Step-by-step explanation:
The journal entries are as follows in the books of Concord Corporation
On June 10
 Merchandise inventory A/c Dr $8,050
 To Account payable A/c $8,050
(Being the inventory is purchased on account) 
On June 11
Merchandise inventory A/c Dr $510
 To Cash A/c $510
(Being freight is paid by cash)
On June 12
Accounts payable A/c Dr $450
 To Merchandise Inventory A/c $450
(Being goods returned is recorded)
On June 19
Accounts payable A/c Dr $7,600  ($8,050 - $450)
 To Cash A/c $7,524  ($7,600 × 1%)
 To Merchandise Inventory A/c $76
(Being payment is recorded)