Răspuns :
X^2-25=X^2-5^2=(X+5)(X-5)
X^2-10+25=X^2-2x5x +5^2=(X-5)^2
X
X^2-25/X^2-10+25=(X+5)(X-5)/(X-5)^2=X+5/X-5 (am simplificat prin (x-5)
X^2-10+25=X^2-2x5x +5^2=(X-5)^2
X
X^2-25/X^2-10+25=(X+5)(X-5)/(X-5)^2=X+5/X-5 (am simplificat prin (x-5)