x,y是有理数,且满足x+2y-y√2=17+4√2
=>(x+2y-17)=(4+y)√2
=>(x+2y-17)=0;(4+y)=0
=>y=-4,x=25
=>（√x+y）的2012次方
=（√25-4)的2012次方
=1的2012次方
=1