Four key bond valuation relationships

Describe the four key bond valuation relationships. Explain why bond prices move inversely to changes in interest rates after watching the YouTube video "Relationship between bond prices and interest rates | Finance & Capital Markets | Khan Academy", hosted by Khan Academy. (200 words needed) : resource needed
Please watch this video:
https://www.youtube.com/watch?v=I7FDx4DPapw&feature=emb_title

Sample Solution