A cura di: Alfredo Bochicchio

$2/5acxx(-5/6b^2c^2+3/2b^2c^2-b^2c^2)$
$(2/5xx-5/6)ab^2c^3+(2/5xx3/2)ab^2c^3-2/5ab^2c^3$
$-10/30ab^2c^3+6/10ab^2c^3-2/5ab^2c^3$
$-1/3ab^2c^3+3/5ab^2c^3-2/5ab^2c^3$
$(-1/3+3/5-2/5)ab^2c^3$
$(-1/3+1/5)ab^2c^3$
$(-5+3)/15ab^2c^3$
$-2/15ab^2c^3$