现化简，在求值，x-2分之3-x除以（x+2-x-2分之5）,其中x=4.
2个回答
展开全部
(3-x)/(x-2)÷[x+2-5/(x-2)]
=(3-x)/(x-2)÷[(x+2)(x-2)/(x-2)-5/(x-2)]
=(3-x)/(x-2)÷[(x^2-4)/(x-2)-5/(x-2)]
=(3-x)/(x-2)÷[(x^2-4-5)/(x-2)]
=(3-x)/(x-2)÷[(x^2-9)/(x-2)]
=(3-x)/(x-2)*(x-2)/(x^2-9)
=(3-x)/(x^2-9)
=-(x-3)/(x^2-9)
=-(x-3)/(x-3)(x+3)
=-1/(x+3)
=-1/(4+3)
=-1/7
=(3-x)/(x-2)÷[(x+2)(x-2)/(x-2)-5/(x-2)]
=(3-x)/(x-2)÷[(x^2-4)/(x-2)-5/(x-2)]
=(3-x)/(x-2)÷[(x^2-4-5)/(x-2)]
=(3-x)/(x-2)÷[(x^2-9)/(x-2)]
=(3-x)/(x-2)*(x-2)/(x^2-9)
=(3-x)/(x^2-9)
=-(x-3)/(x^2-9)
=-(x-3)/(x-3)(x+3)
=-1/(x+3)
=-1/(4+3)
=-1/7
本回答由提问者推荐
已赞过
已踩过<
评论
收起
你对这个回答的评价是？
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
