`a)` Với `x \ne 0,x \ne +-2` có:
`A=([x^2]/[x^3-4x]+6/[6-3x]+1/[x+2]):(x-2+[10-x^2]/[x+2])`
`A=[3x^2-6x(x+2)+3x(x-2)]/[3x(x-2)(x+2)]:[(x-2)(x+2)+10-x^2]/[x+2]`
`A=[3x^2-6x^2-12x+3x^2-6x]/[3x(x-2)(x+2)].[x+2]/[x^2-4+10-x^2]`
`A=[-18x]/[3x(x-2).6]`
`A=1/[2-x]`
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`b)|x|=1/2<=>x=+-1/2` (t/m)
`@` Thay `x=1/2` vào `A` có: `A=1/[2-1/2]=2/3`
`@` Thay `x=-1/2` vào `A` có: `A=1/[2+1/2]=2/5`
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`c)` Với `x \ne 0,x \ne +-2` có:
`A=2<=>1/[2-x]=2<=>1=4-2x<=>2x=3<=>x=3/2` (t/m)
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`d)` Với `x \ne 0,x \ne +-2` có:
`A < 0<=>1/[2-x] < 0` Mà `1 > 0`
`=>2-x < 0<=>x > 2` (t/m)
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`e)A` có giá trị nguyên `<=>1/[2-x] in ZZ`
Hay `2-x in Ư_1`
Mà `Ư_1={+-1}`
`@2-x=1<=>x=1` (t/m)
`@2-x=-1<=>x=3` (t/m)
