The replacement set is 

Replace n in  with each value in the replacement set

and check whether the equation is true. \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \

\ n \		\ True or False \
\ 18 \	\   \	\ False \
\ 19 \	\   \	\ True \
\ 20 \	\   \	\ False \

\

Since n =19 makes the equation true, the solution of is 19

The solution set is .