Question

  Hộ e 2 bài voi mn

Answer 1

7:

a: ĐKXĐ: x<>0; x<>2; x<>-2

\(A=\left(\dfrac{x}{\left(x-2\right)\left(x+2\right)}-\dfrac{2}{x-2}+\dfrac{1}{x+2}\right):\dfrac{x^2-4+10-x^2}{x+2}\)

\(=\dfrac{x-2\left(x+2\right)+x-2}{\left(x-2\right)\left(x+2\right)}\cdot\dfrac{x+2}{6}\)

\(=\dfrac{2x-2-2x-4}{x-2}\cdot\dfrac{1}{6}=\dfrac{-1}{x-2}\)

b: |x-2|=4

=>x-2=-4 hoặc x-2=4

=>x=6(nhận) hoặc x=-2(loại)

Khi x=6 thì \(A=\dfrac{-1}{6-2}=-\dfrac{1}{4}\)

c: A=2

=>x-2=-1/2

=>x=3/2(nhận)

d: A<0

=>x-2>0

=>x>2

e: A nguyên

=>x-2 thuộc {1;-1}

=>x thuộc {1;3}