Explicație pas cu pas:
x'2+7x+6=x'2+6x+1x+6=x×(x+6)+1×(x+6)=(x+6)×(x+1)
x'2+10x+25=(x+5)'2
x'2+6x+9=(x+3)'2
[tex]\it x^2+7x+6 = x^2+6x+x+6 = x(x+6) +(x+6) = (x+6)(x+1)\\ \\ \\ x^2+10x+25 = x^2+10x+5^2= (x+5)^2\\ \\ \\ x^2+6x+9=x^2+6x+3^2 =(x+3)^2[/tex]