a: \(M=\dfrac{2x-4+x+2-x^2}{\left(x+2\right)\left(x-2\right)}=\dfrac{-x^2+3x-2}{\left(x+2\right)\left(x-2\right)}\)
\(=\dfrac{-\left(x-2\right)\left(x-1\right)}{\left(x-2\right)\left(x+2\right)}=\dfrac{-x+1}{x+2}\)
b: |2x-3|=7
=>2x-3=7 hoặc 2x-3=-7
=>2x=10 hoặc 2x=-4
=>x=-2(loại) hoặc x=5
Khi x=5 thì \(A=\dfrac{-5+1}{5+2}=\dfrac{-4}{7}\)
c: Để M>0 thì -x+1/x+2>0
=>x-1/x+2<0
=>-2<x<1
d: Để M là số nguyên thì \(-x-2+3⋮x+2\)
\(\Leftrightarrow x+2\in\left\{1;-1;3;-3\right\}\)
hay \(x\in\left\{-1;-3;1;-5\right\}\)