x²-2x+x-2 x+1
_______ + ____ = 1
(x-2)(x+2) x+2
x(x-2)+(x-2) x+1
---------------- +-------= 1
(x-2)(x+2) x+2
(x-2)(x+1) x+1
------------- + ---------= 1
(x-2)(x+2) x+2
x+1 x+1 x+2
----- + -------- = ------
x+2 x+2 x+2
2x+2=x+2
2x-x=2-2
x=0
vezi:
a²-b²= (a+b) (a-b)
x²-4= x²-2²=(x+2)(x-2)