(3-2根号2)x²+2(根号2-1)x+1=0
[(根号2-1)x]²+2(根号2-1)x+1=0
[(根号2-1)x+1]²=0
(根号2-1)x=-1
x=-1/(根号2-1)
即
x=-(根号2 +1)