Răspuns :
[tex](x^2+x)\cdot[(x^2+x)+6]+9=(x^2+x)^2+6\cdot(x^2+x)+3^2=\\=(x^2+x)^2+2\cdot 3\cdot(x^2+x)+3^2=(x^2+x+3)^2,\;care\;este\;p\u{a}trat\;perfect.[/tex]
Green eyes.
(x^2+x)*(x^2+x+6)+9 =( x(x+1) )*( x(x+1) +6) +9 =
=x(x+1)* (x(x+1) +x(x+1)*6 +9 =
notezi x(x+1) =a=> a*a +a*6+9 =(a+3)^2 = patrat perfect
adica( x(x+1) +3) ^2
^ = ridicat la o putere
=x(x+1)* (x(x+1) +x(x+1)*6 +9 =
notezi x(x+1) =a=> a*a +a*6+9 =(a+3)^2 = patrat perfect
adica( x(x+1) +3) ^2
^ = ridicat la o putere