To many css and js files, Google PageSpeed Insights

Main concern for every business/organisation is “ranking position” and “to be found” on Google. Therefor Google has guidelines which can be found here: https://www.feedthebot.com
When you test “speed” the loading time of your website is measured, in my case the score is 73/100 and that is not okay.

Main reason is
a. too many css files and
b. too many scripts.

My question: can these files be combined to one file?