(1)x-2=-+1
x1=-1;x2=3
(2)(x-2)^2=1/9
x-2=-+1/3
x1=7/3;x2=5/3
(3)x^2+2x-3=0
(x-1)(x+3)=0
x1=1;x2=-3
(4)(x-3)^2=0
x=3