x=(√2-1)/(√2+1)
=(√2-1)²/[(√2+1)(√2-1)] （分母有理化：分子分母同时乘以√2-1)
=(2-2√2+1)/1
=3-2√2
y=(√2+1)/(√2-1)
=(√2+1)²/[(√2-1)(√2+1)]（分母有理化：分子分母同时乘以√2+1)
=(2+2√2+1)/1
=3+2√2

∴xy=(√2-1)/(√2+1)*(√2+1)/(√2-1)=1
x²-xy+y²=3+2√2+3-2√2-1=5最后一步怎么搞得我怎么看不懂哎呀，刚才着急了，忘了一步x²+y²=(3+2√2)²+(3-2√2)²=（9+12√2+8）+（9-12√2+8）=34∴x²-xy+y²=34-1=33