sed delete if matches in next line code example

Example 1: sed delete line before match

Use d option at the end of sed command string for deleting line of matches.
tac | sed -i "" "s/matching_pattern/I+1 d" file.txt | tac #

Example 2: sed delete line with match

Use d option at the end of sed command string for deleting line of matches.
sed -i "" "s/matching_pattern/d" file.txt