Răspuns :
1.[tex] x^{2} + y^{2} +2zy- z^{2} =( x+y)^{2}- z^{2} =(x+y-z)(x+y+z)[/tex]
2.[tex] x^{2} +3x-4= x^{2} -x+4x-4=x(x-1)+4(x-1)=(x-1)(x+4)[/tex]
2.[tex] x^{2} +3x-4= x^{2} -x+4x-4=x(x-1)+4(x-1)=(x-1)(x+4)[/tex]