Answer:

Step-by-step explanation:
Method 1:
Arithmetic sequence is in the form

d is the common difference, can be found by:

Subtituting the
and 
You get:

Method 2 (Mathematical induction):
Assume it is in form 
Base step: 
Inducive hypophesis: 
GIven: 

Proved by mathematical induction

Answer:
2.964
Step-by-step explanation:
Answer:
1 and 9/28
Step-by-step explanation:
you need to put everything over the same denominator
21/28+16/28=37/28
this can be written as 1 9/28
Step-by-step explanation:
One's digit of N can be 2 or 7.
Answer: HK
Step-by-step explanation: