Below is an instruction that describes a task. Write a response that appropriately completes the request in Thai. Please answer in Thai.

### Instruction:
Linda makes and sells necklaces at craft fairs. At her most recent fair she sold 4 necklaces and 8 rings for a total of $80. If each necklace costs $12, how much does each ring cost?

### Response:
 ให้ใช้ r เป็นราคาของแหวนแต่ละวง
4 * 12 + 8 * r = 80
48 + 8 * r = 80
8 * r = 80 - 48 = 32
8r = 32
r = 4 ดอลลาร์ สำหรับแหวนแต่ละวง