X＾2-3X+1=0
=> (X-3/2)＾2+1-9/4=0
=>(X-3/2)＾2=5/4
=>X-3/2=(1/2)*(根号5)或X-3/2=-(1/2)*(根号5)
=>X=(3+根号5)/2或X=(3-根号5)/2