(a-b-c) + (b+c-a)² + (c-a+b)³= (a-b-c) + (a-b-c)² - (a-b-c)³= (a-b-c){1+(a-b-c)-(a-b-c)²}= (a-b-c){1+a-b-c-a²-b²-c²+2ab-2bc+2ac}
