a)[6(x-2)-5(x+1)][6(x-2)+5(x+1)]=(6x-12-5x-5)(6x-12+5x+5)=(x-17)(11x-7)
b) [4(x+5)-3(2x-3)][4(x+5)+3(2x-3)]=(4x+20-6x+9)(4x+20+6x-9)=(29-2x)(10x+11)
c)[5x²-2(x²+2x+3)][5x²+2(x²+2x+3)]=(3x²-4x-6)(7x²+4x+6)
Descompunerea in factori inseamna sa transformama adunarea sau scaderea in produs de 2 sau mai multe paranteze