帮帮我忙: 9.化简1/(a+b)+1/(a-b)-(a-b)/(a^2+ab+b^2)-(a+b)/(a^2-ab+b^2)14.已知a,b,c互不相等,求(2a-b-c)/[(a-b)(a-c)]+(2b-c-a)/[(b-c)(b-a)]+(2c-a-b)/[(c-a)(c-b)]
问题描述:
帮帮我忙: 9.化简1/(a+b)+1/(a-b)-(a-b)/(a^2+ab+b^2)-(a+b)/(a^2-ab+b^2)
14.已知a,b,c互不相等,求(2a-b-c)/[(a-b)(a-c)]+(2b-c-a)/[(b-c)(b-a)]+(2c-a-b)/[(c-a)(c-b)]
答