Sa se arate ca urmatoarea ecuatie este corecta

(x+3)³-(x+3)=(x+3) ((x+3)²-1)=(x+3)(x²+6x+8)***= (x+3)(x²+2x+4x+8)=
=(x+3)(x(x+2)+4(x+2))=(x+3)(x+2)(x+4)=(x+2)(x+3)(x+4) adevarat
*** am considerat cunoscut 9-1=8...:::))