Answer: [tex](-\infty ,-0.12][/tex]
Curved parenthesis for negative infinity. Square bracket for the -0.12
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Explanation:
The inequality [tex]x \le -0.12[/tex] is the same as [tex]-\infty < x \le -0.12[/tex]
This says that x is larger than negative infinity, but smaller than or equal to -0.12
Put another way: x is between negative infinity and -0.12, x could also equal -0.12
To write this in interval notation, we would say [tex](-\infty ,-0.12][/tex]
We always use a curved parenthesis for either infinity. The square bracket indicates "include this endpoint as part of the interval".