Răspuns:
3(x+1)-a(x+1)=
(x+1)(3-a)
b) x²(x-3)-9(x-3)=
(x-3)(x²-9)=
(x-3)(x-3)(x+3)=
(x-3)²(x+2)
d) 3(x+1)+x²-1=
3(x+1)+(x+1)(x-1)=
(x+1)(3+x-1)=
(x+1)(2+x)
f) 6(3x-4)+9x²-16=
6(3x-4)+(3x-4)(3x+4)=
(3x-4)(6+3x+4)=
(3x-4)(10+3x)
h) x²(x+5)-(x²+10x+25)=
x²(x+5)-(x+5)²=
(x+5)(x²+x+5)