Hej Jytte,

This is a math term and would be something like "operatorer i ligningen".

Here is a link to a Microsoft software that works with equations, where they use the term "Hvis du vil justere operatorerne i en ligning, skal du trykke på Skift+Enter, når du starter en ny linje. "
https://support.office.com/da-dk/article/Skrive-indsætte-ell...

Gyldendals store danske siger "operator, (afledt af lat. operari, se operation), i matematikken et symbol, der angiver, at en bestemt proces (operation) skal udføres. "

Hope this helps
Helle