楼主您好:解:因为x²-3x+1=0,所以x≠0所以x²+1=3x(x²+1)×1/x=3x×1/xx+1/x=3(x+1/x)²=3²x²+1/x²+2×x×1/x=9x²+1/x²+2=9x²+1/x²=9-2=7所以x²+1/x²=7祝楼主学习进步
∵x^2-3x+1=0显然x≠0,方程两边同时除以x得:x-3+1/x=0,即:x+1/x=3两边平方得:x^2+2+1/x^2=9,∴x^2+1/x^2=7