Hide field until the checkbox is clicked

Hello!
I have a problem with other elements being hidden.

Fieldname12 is a checkbox with 2 options. If only after a selection option has been clicked, further fields should become visible.

For example:
If fieldname12 – option 1 is clicked, fieldname 8 and fieldname 5 should be visible.

If field name 12 – option 2 is clicked, fieldnames 15 and 16 should be visible.

If none of these two checkboxes are clicked, none of the fields (8,5,15,16) should be visible.

Can someone help me there?

Greetings