ab(a-b)+bc(b-c)+ac(a-c)=a²b-ab²+b²c-bc²+ac(a-c)=b(a²-c²)-b²(a-c)+ac(a-c)=(a-c)(ab+bc-b²+ac)ab(a-b)+bc(b-c)+ac(c-a)=a²b-ab²+b²c-bc²-ac(a-c)=b...