(1)3/(x²-1)(x-2),2/(1-x)(x-2)通分 (2)a+b+c/(a-b)(b-c)(c-a),b/(b-a)(b-c)(

问题描述:

(1)3/(x²-1)(x-2),2/(1-x)(x-2)通分 (2)a+b+c/(a-b)(b-c)(c-a),b/(b-a)(b-c)(

3/(x²-1)(x-2) = 3/(x-1)(x+1)(x-2) ; 2/(1-x)(x-2) = -2(x+1)/(x-1)(x+1)(x-2);a+b+c/(a-b)(b-c)(c-a) = a+b+c/(a-b)(b-c)(c-a); b/(b-a)(b-c)(a-c) = b/(a-b)(b-c)(c-a).