（x-2）²-5（x-2）+4=0
(x-2-1)(x-2-4)=0
x=3 x=6
（x-1）（x+3）=12
（x-1）（x-1+4）=12
(x-1)^2+4(x-1)-12=0
(x-1+6)(x-1-2)=0
x=-5 x=3