Question

Descompuneti in factori: 
a) 2x² +x-1= 
b) xy-x-y+1= 
c) 9xy+3x-3y-1= 

Answer 1

[tex]a)2x^2+x-1=x^2-1+x^2+x=(x-1)(x+1)+x(x+1)=\\ =(x+1)(2x-1)\\ b)xy-x-y+1=x(y-1)-(y-1)=(y-1)(x-1)\\ c)9xy+3x-3y-1=3x(3y+1)-(3y+1)=(3y+1)(3x-1)[/tex]