If you meant to say
, then there are no solutions.
This is because the |5x+1| is never negative. This applies to the result of any absolute value function. Absolute value represents distance on a number line. Negative distance is not possible.
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If you meant to say
, then the steps are shown below
The interval notation would be [-3/5, 1/5] in fraction form
That is equivalent to [-0.6, 0.2] in decimal form.
Use square brackets to include each endpoint.