Question

a)

b)

Answer 1

`a)[x+3]/[x+1]+[x+2]/x=2`         `ĐK: x \ne -1;x \ne 0`

`<=>[x(x+3)+(x+2)(x+1)]/[x(x+1)]=[2x(x+1)]/[x(x+1)]`

   `=>x^2+3x+x^2+x+2x+2=2x^2+2x`

`<=>4x=-2`

`<=>x=-1/2` (t/m)

Vậy `S={-1/2}`

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`b)[x+3]/[x-3]-[x-3]/[x+3]=9/[x^2-9]`        `ĐK: x \ne +-3`

`<=>[(x+3)^2-(x-3)^2]/[(x-3)(x+3)]=9/[(x-3)(x+3)]`

  `=>(x+3-x+3)(x+3+x-3)=9`

`<=>6.2x=9`

`<=>12x=9`

`<=>x=3/4` (t/m)

Vậy `S={3/4}`