You hv been given n=2 an Tn=5,n=3 an Tn=7,n=4 an Tn=9,n=7 an Tn=A,n=10 an Tn=21,n=B an Tn=153 determine A and B help please

so, we have

n Tn
2 5
3 7
4 9
7 A
10 21
B 153

From the first three terms, it looks like

Tn = 2n+1

T10 also fits this, so we have

7 15
76 153