写成７项的：𝑓÷3³＝((b-c)*(c-a)*(a-b)-(a*(e^2-f^2)+b*(f^2-d^2)+c*(d^2-e^2)))^2+((2*(a-b)*(a-c)*d+(b+c-2*a)*e*f+d*(e^2+f^2-2*d^2))^2+(2*(b-a)*(b-c)*e+(c+a-2*b)*f*d+e*(f^2+d^2-2*e^2))^2+(2*(c-a)*(c-b)*f+(a+b-2*c)*d*e+f*(d^2+e^2-2*f^2))^2)+15*(((b-c)*e*f+d*(e^2-f^2))^2+((c-a)*f*d+e*(f^2-d^2))^2+((a-b)*d*e+f*(d^2-e^2))^2)．
