7/1資本公積-庫藏股交易貸餘=($25-$20)×10,000×1/2=$25,000
7/13資本公積-庫藏股交易借餘=($20-$15)×4,000=$20,000
12/31資本公積-庫藏股交易貸餘=$25,000-$20,000=$5,000
5000