1. (a-1)(a³+a²)=a²(a-1)(a+1)
2. (a+1)[(a+1)(a-3)-a-3]=(a+1)(a²-3a-6)
care daca calculezi a doua paranteza nu are 2 radacini
3. (2b+5)(4a-1)(2b+4)
4. -x(-x+1)³-x(-x+1)²+x(-x+1)=-x(-x+1)(x²-2x+1+x-1+1)=-x(-x+1)(x²-x+1)
5. (x+1)²(x+1+x-1)=2x(x+1)(x+1)
6.(x-3)(x²+x+1+x²-1)=x(x-3)(2x+1)
7.(x+1)(x²+2x+1+x+1-2)=x(x+1)(x+3)