Question

Descompuneti in factori:
1. xy-x-y+1
2. 9xy+3x-3y-1
3. (x-2)^2-4x^2
4. x^3+x^2-16x-16

Answer 1

1. xy-x-y+1=x(y-1)-1(y-1)=(y-1)(x-1)
2. 9xy+3x-3y-1=3x(3y+1)-1(3y+1)=(3y+1)(3x-1)
3. (x-2)^2-4x^2=(x-2-2x)(x-2+2x)=(-2-x)(-2+3x)
4. x^3+x^2-16x-16=x²(x+1)-16(x+1)=(x+1)(x²-16)
Bafta! ;)