Here is a link to the playlist of video explanations to all of the math questions in the 2020 December ACT (Form D03) Test.

 
Here is a link to the playlist of video explanations to all of the math questions in the 2020 July ACT (Form C01) Test.

 
Here is a link to the playlist of video explanations to all of the math questions in the 2020 June ACT (Form C02) Test.

Here is a single image that summarizes why I recommend everyone to prepare for the ACT by practicing with official ACT tests.

 
Here is a link to the playlist of video explanations to all of the math questions in the 2019 June ACT (Form B02) Test.