早教吧 育儿知识 作业答案 考试题库 百科 知识分享

异分母分式的加减计算.1÷(x+2)-2÷(x-2)x-2-x^2÷(x-2)计算(4/a^2-4)+(1/2-a)1÷(x+2)-2÷(x-2)x-2-x^2÷(x-2)(4/a^2-4)+(1/2-a)

题目详情
异分母分式的加减计算. 1÷(x+2)-2÷(x-2) x-2-x^2÷(x-2) 计算(4/a^2-4)+(1/2-a)
1÷(x+2)-2÷(x-2)

x-2-x^2÷(x-2)

(4/a^2-4)+(1/2-a)
▼优质解答
答案和解析
1÷(x+2)-2÷(x-2)
=[(x-2)-2(x+2)]÷[(x+2)(x-2)
=(-x-6)/(x²-4)
x-2-x^2÷(x-2)
=[(x-2)²-x²]÷(x-2)
=(-4x+4)/(x-2)
(4/a^2-4)+(1/2-a)
=[4-(a+2)]/(a²-4)
=(2-a)/(a+2)(a-2)
=-1/(a+2)