原式可化为(5x-3)^2-2(5x-3)+1-1=0(5x-3-1)^2=1(5x-3-1)=1或者（5x-3-1）=-1解之得x=1或者x=3/5
（5x-3）^2-2(5x-2)=0(5x-3)(5x-3-2)=0x1=3/5 x2=1
