PLEASE HELP ME I REALLLY NEED TO DO THIS I WILL GIVE THE CORRECT ANSWER BRAINLY PLEASEEEEE

Answer:
21 is the correct answer
it's just a logical question
just do multiply with 2 and add 1
answer will come
as above:4 is given
4×2+1
8+1
9
second:12
12×2+1
24+1
25