A cura di: Alfredo Bochicchio

$4/25x^6-6/5x^3y^2+9/4y^4$
$4/25x^6=(2/5X^3)^2$
$9/4y^4=(3/2y^2)^2
$6/5x^3y^2=$doppio prootto
$(2/5x^3-3/2y^2)$