(x+3)²+(x-5)(x-1) =
= x²+6x+9 + x*x+x*(-1)+(-5)*x+(-5)*(-1) =
= x²+6x+9+x²-x-5x+5 =
= 2x²+14 = 2(x²+7)
La (x+3)² am aplicat formula (a+b)² = a²+2ab+b², iar la urmatoarele doua paranteze am inmultit element cu element.
