Where can I use the formulas taught in 'Introduction to DAX: DAX tables and filtering'?

[Anonymous]

I'm doing the 'Introduction to DAX' guided learning, and it's largely very good, but the section called 'DAX tables and filtering' (https://docs.microsoft.com/en-us/power-bi/guided-learning/introductiontodax?tutorial-step=6) gives no clear indication of where the formulas displayed should be placed. I assumed you should use the SUMX(FILTER()) formulas and the others to create new tables, but, using the exact dataset and functions from the video, Power BI is telling me that they're not valid table expressions. I checked the new column and new measure features, but the formulas provided don't work in any of them.

Does anyone know where I'm supposed to apply this information?