How to find Account records that didn't had any closed tasks or events in the last 7 days in Salesforce?

Last Activity
The date when a User last did something related to the record (represents one of the following):

1. The latest Due Date of the Closed Tasks on a record.
2. The latest Date of Events on a record.
 
1. Create a Report.

2. Add Last Activity as the filter with LAST 7 DAYS.
 
 
Output: