Step-by-step explanation A closed interval is one that includes its endpoints,. An open interval is one that does not include its endpoints
![\begin{gathered} (a,b)\rightarrow open \\ \lbrack a,b\rbrack\Rightarrow closed \end{gathered}]()
Step 1
a)
![0\leq x](https://img.qammunity.org/2023/formulas/mathematics/college/5pse1gfbqda5dty91o2xvn758kfltcchin.png)
this inequlity represent all the values greater or equal than zero , so from zero to positive infinite
![\lbrack0,inf)](https://img.qammunity.org/2023/formulas/mathematics/college/dbjkuty1kikbfmie7n4ks97n6k944j2e2u.png)
Step 2
b)
![x\leq8](https://img.qammunity.org/2023/formulas/mathematics/high-school/9g55l2jlr7xodkcd4hpxcm9a29hesatnoq.png)
all the values smaller or equal than 8, so from negative infinite to eighth
![(-inf,8\rbrack](https://img.qammunity.org/2023/formulas/mathematics/college/jpzcby1g7t2xp5a4r4tgrcmgsesrhrr607.png)
c)
![-4all the values greater than -4 ( note that -4 is not included, so open interval)[tex](-4,inf)]()
d)
![12\leq x](https://img.qammunity.org/2023/formulas/mathematics/college/6qb4d70ilaholsxyewvxz7u5tnbn6y38eh.png)
all the values greater or equalto 12
![\lbrack12,inf)](https://img.qammunity.org/2023/formulas/mathematics/college/3g4i7ly7cla4vl12t59n4f3he6ljol8czt.png)
e)
![x\leq8](https://img.qammunity.org/2023/formulas/mathematics/high-school/9g55l2jlr7xodkcd4hpxcm9a29hesatnoq.png)
all the values greater or equal to -8, hence
![(-inf,-8\rbrack](https://img.qammunity.org/2023/formulas/mathematics/college/hnltjv1h3fnm916hkjmqapdjv1sisfxwl6.png)
I hope this helps you