初二数学,就两题,急急急,过程
展开全部
(1)1/(a-b) - (a+b)/(a-b)^2 - (a+2b)/(a^2-b^2)
= (a^2-b^2 - (a+b)^2 - (a+2b)(a-b)))/(a+b)(a-b)^2
= (a^2-b^2 -a^2-b^2 -2ab - a^2 - 2ab + ab + 2b^2) / (a+b)(a-b)^2
= (-a^2 - 3ab ) / (a+b)(a-b)^2
= -a(a+3b) / (a+b)(a-b)^2
(2)1/(x-1) + 1/(x-2) - (x+3)/(x^2+x-2)
= 1/(x-1) + 1/(x-2) - (x+3)/(x+2)(x-1)
= (x^2-4 + (x+2)(x-1) - (x+3)(x-2)) / (x+2)(x-1)(x-2)
= (x^2-4 + x^2+x-2 - x^2-x+6) / (x+2)(x-1)(x-2)
= x^2 / (x+2)(x-1)(x-2)
答题不易,请及时采纳,谢谢!
= (a^2-b^2 - (a+b)^2 - (a+2b)(a-b)))/(a+b)(a-b)^2
= (a^2-b^2 -a^2-b^2 -2ab - a^2 - 2ab + ab + 2b^2) / (a+b)(a-b)^2
= (-a^2 - 3ab ) / (a+b)(a-b)^2
= -a(a+3b) / (a+b)(a-b)^2
(2)1/(x-1) + 1/(x-2) - (x+3)/(x^2+x-2)
= 1/(x-1) + 1/(x-2) - (x+3)/(x+2)(x-1)
= (x^2-4 + (x+2)(x-1) - (x+3)(x-2)) / (x+2)(x-1)(x-2)
= (x^2-4 + x^2+x-2 - x^2-x+6) / (x+2)(x-1)(x-2)
= x^2 / (x+2)(x-1)(x-2)
答题不易,请及时采纳,谢谢!
推荐律师服务:
若未解决您的问题,请您详细描述您的问题,通过百度律临进行免费专业咨询