初二代数计算

题目

初二代数计算
（1）(b-c)/(a²-ab-ac+bc)-(c-a)/(b²-bc-ab+ac)+(a-b)/(c²-ac-bc+ab)
(2)1/a+1/b(1+1/a)+1/c(1+1/a)(1+1/b)+1/d(1+1/a)(1+1/b)(1+1/c)-(1+1/a)(1+1/b)(1+1/c)(1+1/d)

答案

(1)(b-c)/(a2-ab-ac+bc)-(c-a)/(b2-bc-ab+ac)+(a-b)/(c2-ac-bc+ab)
=b-c/(a-b)(a-c)-(c-a)/(b-a)(b-c)+(a-b)/(c-a)(c-b)
=(b-c)2-(c-a)2+(a-b)2/(a-b)(a-c)(b-c)
=2b/(a-c)(c-a)
(2)
-(1+1/a)(1+1/b)(1+1/c)(1+1/d) 什么