The replacement set is

Replace a in  with each value in the replacement set and check

whether the equation is true or not. \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \

\ a \	\ \	\ True or false \
\ 14 \	\ \	\ False \
\ 16 \	\ \	\ False \
\ 18 \	\ \	\ True \
\ 20 \	\ \	\ False \

\

Since a = 18 makes the equation true, the solution of  is 18.

The solution set is.