`- 1 < 2x + 3 < 6`

Subtract `3` from all 3 sides

`- 1 - 3 < 2x + 3 - 3 < 6 - 3 ` `- 4 < 2x < 3`

`- 4 < 2x < 3`

Divide all sides by `2`

`-2 < x < 3/2`

The solution graph:

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