Second, according to the meaning of the question, set variables and list functional relationships. If there are multiple variables, multiple relationships are required, and then the relationships are simplified by mathematical means such as elimination;
Third, do more typical topics, think more, analyze more and summarize more. Remember: Practice makes perfect!
You can call me if necessary. I have kept many typical examples of moving points. Finally, I wish you find the key to solve the power problem as soon as possible ~ ~ ~